Fallout's getting the Obsidian RPG treatment with New Vegas, which isn't too far off. (Though I think they're sticking to F3 style gameplay)
I think the "Acts of Caine" universe created by Matt Stover ("Heroes Die", "Blade of Tyshalle", "Caine Black Knife") would make for one of the most epic RPG settings ever. It features a brilliant blend of fantasy and sci-fi, detailing a dystopian future Earth with a rigid caste system alongside a parallel traditional-ish fantasy world.
Hugely powerful entertainment studios train individuals to pass as inhabitants of "Overworld" - a parallel world discovered years previously. They're taught the languages, the history, the traditions... and they're trained how to kick ass, be it with magic or weapon. Once they're ready, they become "Actors". They get sent to Overworld on "adventures", implanted in such a way that they can provide first-person feedback of their experiences and thoughts back to their audiences on Earth. A lot of them are eventually killed but that's part of being a highly (or not so highly) paid entertainer: and it always pays off in the ratings. Unaware as it is of Earth's existence, Overworld is basically treated as a giant sandbox to generate entertainment and profit.
I haven't remotely done the setting justice with the above description. Suffice to say, it's awesome and "Heroes Die" remains one of the greatest fantasy novels I've ever read.
Oh, and bump.