But then, Carrie Bradshaw finally landed Mr. Big, the entire Fisher family died, Tony Soprano stopped believin’ in a New Jersey diner, and Tommy Carcetti became governor of Maryland.

By the time Sue Naegle arrived from United Talent Agency to take the network’s top job in 2008 (alongside co-president Richard Plepler and president of programming Michael Lombardo), the programming larder was looking bare. “We walked into a schedule that was mostly empty,” she told The Observer. And what could be better? “From a development and programming perspective, that’s the dream.”

Recently the network has gone on something of a programming binge, putting forth its most aggressive new slate in memory. Luck, the horseracing drama from director Michael Mann and creator David Milch, debuted in January to respectful reviews and strong ratings; it was then swiftly renewed for a second season—then even more swiftly cancelled last week due to the on-set deaths of three horses (or perhaps, some speculated, due to a precipitous drop in viewers). Last month saw the debut of a new Ricky Gervais comedy, Life’s Too Short (his third for the network), and next month, HBO will debut two new comedies, the youth-oriented Girls and the political farce Veep, as well as the second season of the fantasy epic Game of Thrones. Summer will bring Aaron Sorkin’s latest look behind the scenes of something (this time it’s a cable news show). An adaptation of The Corrections is filming now, and A Visit From the Goon Squad is reportedly in development.

It's about time. HBO, which got its start airing heavyweight boxing matches, came out swinging. After years in which the broadcaster came to define quality television, its lessons are visible up and down the dial. The hourlong contemporary adult drama in The Sopranos mold is now standard-issue. The buzziest Sunday night drama this year was Downton Abbey, on PBS.

The competition will heat up still further later this year, when Netflix debuts an hourlong drama of its own, the David Fincher-directed House of Cards, to be followed by the revival of Arrested Development and the women-in-prison series Orange Is the New Black. (Original programming from Hulu and Amazon is said to be just around the corner.)

But between HBO’s genre hits (Game of Thrones, True Blood), its sepia-toned period curios (Luck, Boardwalk Empire), its noble if ignored charity efforts like the New Orleans drama Treme, and its low-risk comedies (whatever passing fancy Ricky Gervais happens to alight upon), HBO now seems as unsure of how to present itself to the world as Carrie ransacking her shoe closet—and at the very moment networks like Showtime, AMC and FX are ascendant.

Did every channel learn from HBO’s success except for HBO?

“Their brand to me is, truthfully, a little bit dated version of high quality,” said Mo Ryan, a longtime Chicago Tribune television critic, currently at the Huffington Post. “HBO is doing what HBO does: hire big-name talent to do expensive projects, and take chances on a few things that don’t cost them very much money. Their approach is safe and predictable. That leads to competent programming, but it doesn’t lead to the next Homeland.”

Showtime’s hyper-paranoid counterterrorism thriller picked up the Best Drama Golden Globe this year and has put a creative defibrillation paddle to that network’s collection of aging hits. Those series, greenlit by Showtime’s former president of entertainment, Robert Greenblatt, gave the network a clear identity, hinging on dramedies about women with secrets—Weeds, Nurse Jackie and The Big C among them—and blood-and-camp drama tentpoles like Dexter and The Tudors. (Mr. Greenblatt has since been called to the majors and is now running NBC.) Other competitors have also used programming to brand themselves. AMC does meditative and highly watchable dramas about men in difficult situations (The Walking Dead, Breaking Bad, Mad Men), for instance, whereas FX has specialized in black comedy and heightened violence (Justified, Louie, and the departed Nip/Tuck and The Shield).

HBO is still an extremely valuable component of Time Warner, and its subscriber numbers remain the highest on premium cable. But rivals are gaining ground. In the final quarter of 2011, HBO added 190,000 subscriptions after two declining quarters (just in time for Game of Thrones), while Showtime and Starz added 700,000 and 595,000, respectively. (That said, Starz and Showtime are more flexible in setting promotional rates with cable providers.)

In part the problem appears to be one of marketing: Having seen its longstanding identity—as the home of quality entertainment for grown-ups—adopted by so many upstarts, the channel seems to have lost its bearings. When asked about HBO’s brand, Ms. Naegle replied, “I think about this a lot.” She cited the series Enlightened, a half-hour program starring Laura Dern, as one that is core to the network’s identity. “I don’t think that show could exist any other place,” she said, noting that within HBO, it was called “a half-hour hour,” presumably in light of its unusual mix of big themes and a stunted running time.

“For us, it’s a signature HBO show,” she added. “But I don’t think everything needs to have a signature feeling.”

The brainchild of director Mike White, Enlightened centers on a spiritually adrift woman in a competitive, ugly world. It’s a frequently brilliant show, but a quirky one—seeming at times custom-made to be unjustly ignored. It was recently renewed for a second season despite averaging fewer than 200,000 viewers per episode.

But the show exemplifies HBO’s longtime strategy of cultivating relationships with talented showrunners and letting them do more or less whatever they want. Mr. White, who was one of Ms. Naegle’s clients when she was an agent, said that he’d received precious few notes on the series. “They were just along for the ride,” he said.

Alan Ball of True Blood (who’d also been represented by Ms. Naegle), said that the only network notes he received for his show about sexed-up vampires and werewolves tended to ding him for not going far enough, an unusual critique from a network, and a welcome one. True Blood is HBO’s biggest hit, but Mr. Ball is more focused on art than commerce. “I don’t care about the number of people who watch the show,” he said. “I’d rather have a smallish audience than a gazillion people.”

The network’s taste for heavyweight talents hasn’t always worked out. For every True Blood, there’s been a Treme or two. Meanwhile, TV’s breakout series have lately come from writers’ room veterans stepping up to run their own shows, a group that is in short supply on HBO these days. “Where is the talented writer-producer who no one’s ever heard of who has industry experience?” asked Ms. Ryan, citing Vince Gilligan, the creator of Breaking Bad, as a case in point. An equally apt example might be Matthew Weiner, who was hired to write for The Sopranos on the basis of his spec script for Mad Men, a project HBO ultimately turned down.

One could write an alternate history of HBO beginning on June 10, 2007, in which Mad Men—or an equally groundbreaking series—made its debut immediately following The Sopranos' finale. Former chairman and CEO Chris Albrecht had resigned just a month before, following an arrest for domestic violence, and president Carolyn Strauss would soon be ousted. After The Sopranos cut to black, though, HBO introduced the world to John From Cincinnati, a faux-mystical surfer drama created by Deadwood auteur David Milch.

The post-Albrecht, post-Tony period was a time of reckoning for HBO, not least because Mad Men also premiered that summer. Ms. Naegle told The Observer that the first script she read for HBO—during a Mexican vacation she took just before starting the new gig—was Game of Thrones, which grew into a flagship hit. “These shows bring 10-part movies into your home every Sunday night. They are big shows,” she said, adding that both Game of Thrones and Luck were logistically difficult but worthy of the network’s efforts. “With Luck, we’re dealing with horses! They don’t behave like actors.”

She was right about that. Shortly after we spoke, a third horse died and the show was cancelled.

The lesson? Placing a big bet on a tested thoroughbred might seem like a prudent move, but anything can happen when the horses round the home stretch. Ms. Ryan defined Boardwalk Empire as an exemplar of the sort of big HBO bet—a visually complex and lavish melodrama, studded with marquee names—that has increasingly failed to pay off. “It’s a structural exercise that does not have a vibrant emotional core,” she said. “That’s emblematic of what’s wrong with HBO. I just don’t get a spark from it.”

Among those working to fill the void is Starz, under the leadership of none other than Mr. Albrecht. “Instead of being all over the place in our originals, we’re trying to concentrate on ones that are larger-than-life, theatrical, fun, and entertaining,” Mr. Albrecht told The Observer of shows like Boss and Spartacus. “Those are the words we’re using for our brand.”

The game has changed since Mr. Albrecht was running HBO. “At that time, we were just looking for great shows with great show-runners and trying to bring a different sensibility into the way shows were originated,” he said. And to some extent, that spirit remains. Girls creator Lena Dunham didn’t even have a pitch prepared when she first met with Sue Naegle. “I wasn’t pounding the pavement trying to get Girls out there,” said Ms. Dunham, whose show is also produced by comedy consigliere Judd Apatow. “What HBO does is champion a creator,” she added.

Ms. Dunham, who wrote, directed and stars in her show, has become an indie darling due to the critical success of her irresistible debut film, Tiny Furniture. Still, it remains to be seen whether her propensity for emotional unguardedness and ribald humor will play among mainstream audiences. In one episode, a character brings cupcakes to an abortion clinic for an impromptu party; another character is portrayed as a dolt for being obsessed with Sex and the City (she calls herself a Carrie). Asked about the double-edged homage, Ms. Dunham said, “It was our way of going, ‘We get it, these are our predecessors.’” But Sex and the City was television for the masses; Girls is a boutique entertainment for what is likely to be a tight-knit cadre of devoted fans.

Not that such numbers necessarily trouble the boss. “Our passion for shows is not about proving ratings success,” Ms. Naegle said. “Really it’s about how we’re feeling about something creatively and how we feel about something fitting into our brand.”

HBO hasn’t had a zeitgeist-hit comedy since Entourage—and longtime favorite Curb Your Enthusiasm is prone to long hiatuses. We asked Ms. Naegle why more recent efforts—like the just-canceled trio Hung, Bored to Death, and How to Make It in America, the various Ricky Gervais series, and Enlightened—had had a hard time connecting with audiences.

“What’s your definition of HBO comedy success?” she asked.

We cited Carrie, Larry, and Vinnie.

“You would say something that feels like it’s generating something culturally,” she said. “Cable comedy has had a broader definition of success. With Girls and Veep, I’m not putting extraordinary pressure on the shows to perform in a way shows in the past have.” She added, however, “Eastbound and Down gets great numbers.”

Where HBO has enjoyed some branding success is in the area of original movies. Brian Lowry, Variety’s chief TV critic, noted that the one-off films, while not broadly popular, are central to HBO’s image as a high-class outfit: “That’s the only reason the movies exist, strictly so they can show they have movie stars. Game Change was a good rating for HBO, two million viewers. But the bigger payoff was that it was on every goddamn cable network. Someone said to me once, pay cable is like a really nice coffee table book. You don’t always have to be flipping through it to be glad you have it.”

The original movies also tend to fare well during awards season, where HBO’s series have lately been passed over. AMC and Showtime both leapfrogged the network in terms of total nominations for series programming in 2010, and Mad Men has taken the Best Drama statue four times running—most recently defeating Boardwalk Empire and Game of Thrones.

It’s one more way in which HBO’s brand identity is slowing eroding, which might be the network’s biggest problem of all—especially as the ascendancy of à la carte viewing platforms like DVRs, Netflix, Hulu, and AppleTV separate programming from its source. “Brands are and will become increasingly more important as technology continues to disconnect networks from our individual attributes,” Mr. Albrecht explained. “What we would like to be is not commoditized as the pieces but commoditized as the brand.”

In the early days, Mr. Albrecht recalled, “the brand at HBO was ‘It’s not TV.’ A lot of people have copied that mantra even if they’re not stating it. In a sense, as HBO has dropped it, everything is trying to not be TV.”

The network that redefined television recently rolled out a new slogan: “It’s HBO.” The ardent hope among TV fans is that that’s still enough.

"Six Feet Under"

Remember Six Feet Under? At the time of its airing, the show was one of the holy trinity of HBO's ascent, alongside the equally loved Sex and the City and The Sopranos. After a shaky last couple of years, Six Feet Under has been relegated to the bottom of the memory bin, with revisionists claiming that HBO rose to acclaim on the back of The Sopranos and The Wire (which people loved, but which was not a "sensation" at any point).

That's perhaps the problem. Six Feet Under dealt with so many taboos, and so many of those taboos so hamhandedly, that it feels very much like a period piece now, both in the Bush-II-era-liberal preoccupations of its characters and the dramaturgical style of family members shocking one another constantly. That said, we loved Six Feet Under in its initial airing for its "honesty" about how things are, or would be if one were a commitment-phobic mortician with a nightmare family, and we love it now for the way it reminds us that really good art (and we really, REALLY use that word sparingly vis-á-vis television) does not really rely on reputation to move.

Tonight's episode on HBO Signature is one from the rather unfairly maligned fifth season, wherein Nate and Brenda debate the fate of their possibly-disabled unborn baby (more intriguing than the baby plot should be!) and Claire sacrifices that which makes her so Claire-y to embark upon a dully traditional relationship. By season 5, the show had shed its more gothic trappings and become a good opportunity to hang out with recognizable, if occasionally awful, people. It's the kind of TV one remembers and speaks of fondly years later--so watch it if you get this super-premium channel!

Set your DVR for HBO Signature at 8pm.

It didn’t quite work out that way; the shoe selection, though marked down an additional 40 percent, was still mostly out of my price range, and seemed heavily skewed in favor of really, truly impractical shoes, like 5-inch stilettos with ultra-thin metal heels—they looked like they would be good for self-defense (a person kicked in the balls with them would definitely have to be taken to the hospital) but not for actually, you know, walking in.

After I decided that I in fact didn’t need a pair of metallic pewter Manolo Blahnik high-heeled sandals that were 75 percent off and yet still half a size too big, I made my way over to the clothing section, which had way too many of the same Rag & Bone studded dresses and too few of the perfect black Phillip Lim cocktail dresses that I had invented in my mind. But even though the pickings were slim, I acquired a pile of stuff and headed to the makeshift dressing room—just a corner of the sales floor with a few full-length mirrors along the walls. I hung my clothes up on the rack and started attempting to pull a too-small Diane von Furstenberg satin dress over my head.

“Excuse me, do you mind if I ask you—do you like this?” The speaker, whom I’ll call Amy, was a short, skinny, dark-haired woman with tattoos on her arms, who was trying on a sleeveless party dress that appeared to have been Bedazzled with oversize rhinestones.

“It looks nice,” the other woman, whom I named Pauline in my head, said noncommittally.

“I just can’t decide,” said Amy. “I mean, it’s expensive. It’s really expensive. It’s more than I’ve ever spent on a dress in my entire life.”

Pauline nodded sympathetically.

Amy looked at herself in the mirror again. “Oh, I just don’t know what to do. See, it’s my 40^th birthday party in a couple weeks, and I just want to be wearing the dress that when people see me, they just go, wow. You know? I want that dress.”

“Oh, I know what you mean,” said Pauline.

“It’s just so expensive. I mean, even with the discount, it’s still, like, $500! So it’s like … do I get the dress or do I pay my rent this month, you know?” Someone else chimed in that it might be better to get the dress. Anonymous shopping-enabling at work!

“I should get it, right?” Amy had an audience now. “I mean … I have a photo of this dress as my screensaver on my computer!”

“Oh, you have to get it then!” said someone else.

“Well,” said Amy, looking at herself in the mirror, “I’m never getting married. I’m never going to have a wedding. So this is sort of like my wedding dress, you know?” Sympathetic murmurs from the crowd. “I’m turning 40. I just want a dress where people are really like, wow,” she said again. “Is this that dress? Do you think this is that dress?”

It was sort of like that Sex and the City episode where Carrie registers for a pair of Manolos (then I was really glad I hadn’t bought them) because hers had been stolen at her friend’s baby shower and, she rationalizes, she should be allowed to have a wedding … to herself. True, Amy wasn’t asking her friends or anyone else to purchase this dress for her, but there was something about the idea of what you might call liberated materialism that scared me.

I told my wise friend Marisa this story and asked what she thought. Was I being judgy? Or—and this was harder to swallow—maybe I was projecting my own insecurities about getting married onto this woman? “Maybe there’s a little joy in being able to pick out your own dress at Barneys and not some frothy confection of a wedding dress, you know?” Marisa said.

When I was growing up, my mom had a friend, a successful TV writer named Meryl, who had never gotten married. (She was my mom’s only single friend, I think, and her existence was treated as a sort of cautionary tale: Crazy single New York ladies buy too-tight Chanel suits and also wear leggings and mules.) By the time I remember meeting her, she was probably in her late 30s, living alone on the Upper East Side. Meryl liked to call my mom crying and tell her how lucky she was that she was married and had kids. One day, in the mail, my mom got an invitation to Meryl’s 40^th birthday party; on the invitation, Meryl had indicated a jeweler to which her invited guests could send money so Meryl could purchase her chosen necklace. “Well, why shouldn’t I?” she told my mom. (Oh, I don’t know, maybe because it’s tacky and you already have more gaudy jewelry than you know what to do with, and the only reason you’re doing this is to remind people that you, Meryl, were dealt a bad hand in life and everyone should feel sorry for you?)

Amy, the Barneys woman, seemed positively enlightened in contrast.

“I mean, it could be a liberating moment and not a pathetic one,” said Marisa, as we mulled the question of the dress some more. “But I also think it shouldn’t be that Sex and the City feminism equals choosing my choice … to buy my luxury goods. Choosing our choice is way more expensive than TV made it out to be.”

It occurred to me that we, the post–Sex and the City generation, are sort of stuck. How are we supposed to know if we are unmarried because we want to be? As an unmarried 30-something woman in New York, you can’t say you want to get married, because then you’re that unmarried 30-something woman in New York who’s obsessed with marriage. But if you go around saying you don’t want to get married, people think you’re lying, or that you’re so traumatized by your past dating experiences that you must hate men. (Perhaps related: Most of my friends were completely captivated by Ariel Levy’s story in The New Yorker last week about the Van Dykes, the roaming pack of separatist lesbians. But today I think we’re all afraid we’d end up like Ruth on Six Feet Under, when she thinks her friends are serious about starting a women-only compound in Topanga.)

Or maybe my generation is just too concerned with what other people think.

dshafrir@observer.com

The Hollywood Reporter writes: