Ask HN: Good books?

I just finished reading Atlas Shrugged, which I thought was a fantastic book. I'm reading Another Roadside Attraction now on the recommendation of a friend, but I think I want to read some non-fiction next, or at least eye-opening fiction. I'm thinking about some Bertrand Russel, Richard Feynman, or books on philosophy, human behavior, or economics.

What are some good books that you've read that are ground breaking, thought provoking, or changed the way you think/look at things?

ps: you can check out my shelf at shelfari.com/herms