Definitely some great stuff already mentioned here as favorites.
Usually if I am asked for a favorite I say there are too many to pick just one, I love so many books in different ways.
But if I have to choose just one, it would be Les Miserables. I read it when I was 18, so I'm sure that made a difference in how it affected me. Its a beautiful story, beautifully told. What more could you ask for?
A couple of others are Walden, War and Peace, Catch 22 and one I want to mention that is not so famous is a book called the River Why by David James Duncan. Its very philosophical and also hilarious in a very original way.
This thread has made me think I should go back and re-read Catcher in the Rye too.
Anyone interested in talking books, feel free to write me : )