The Greek collector Dimitris Daskalopoulos is known to be one of the more modest art investors of Hellenic extraction. He doesn’t have a 115-foot superyacht that Jeff Koons designed for him named “Guilty,” for instance—that would be his fellow Athenian, Dakis Joannou. What Mr. Daskalopoulos will have after tonight, though, is a Leo Award, the annual prize handed out to a prominent collector by Independent Curators International (and named, of course, for Leo Castelli). It all goes down at a swank dinner affair, where Agnes Gund will present Mr. Daskalopoulos with the award.