The funny thing about nostalgia is you probably already own the game, and are hesitant to buy it.
But if you never played it, it may not sound appealing, or it may not be enjoyable to play.
For me, the only title that is awesome that I don't own is Gunstar Heroes.
I would like to see rpgs I never got a chance to play, neogeo titles that were too expensive and games that never made it to the us but should have.