After what magic The Witcher worked with its book-to-video-game adaptation, I'm really looking forward to what Metro 2033 comes up with. Even though I think that "book" was more of a blog to begin with.
It occurs to me that a lot of good games are born out of direct adaptations of books as well as spun off of inspirations that come from books. But don't let me waste your time try to list them - let GamesRadar's list of "Top 7 Games Based On Books" do that instead.
By far the "best" game on that list for me is American McGee's Alice - with The Witcher in a close second (and only because the original adaptation of the anthology was so lousy). Rainbow Six makes the cut, naturally. But I have to admit I didn't know about that Hitchhiker's Guide To The Galaxy game. Tragic!
Enjoy the read: The Top 7… Games based on books [GamesRadar]