On the surface, it seems to be nepotism. Subterranean sits on Delmar, just across the street from the RFT offices in University City, and so it is a lunch-hour haven for the bookish (guilty) and an easy out for lazy reporters (guilty again). But Subterranean honestly and truly deserves the award, and here's why: If you have three bucks and an hour to kill, you will kill it thoroughly at Subterranean, and you will have something to show for it when you walk out. Yes, if you want bargain-priced sci-fi paperbacks, the Book House in Rock Hill (9719 Manchester Road; 314-968-4491) is a better bet; if you want beautiful hardcover books about local history, you can't go wrong with Dunaway Books. But if you have no idea what you want other than the general "I'd like something new to read" idea that grips you on lazy Tuesday afternoons, you can't beat Subterranean. They've got a little bit of everything -- from erotica to fiction to surrealism to natural history to sociology to music criticism to sci-fi to witchcraft, et cetera. The staff of three is knowledgeable, friendly and chatty but never obsequious. And the chairs in the front window are exceptionally comfy. Subterranean wins this year's honor because they earned it.