Lots of good suggestions in this thread. I'd second the various mentions of Ken Kesey's two novels, One Flew Over the Cuckoo's Nest and Sometimes A Great Notion. If Kesey weren't already remembered primarily as the leader of the Merry Pranksters, he'd be remembered as a great American novelist. Both novels celebrate individual freedom and rebellion against overbearing institutions, which is a quintessentially American theme.

Even if it was intended primarily as a poke in the eye to his liberal friends, Doug's listing of Karl Rove's book blows my mind.