Books that stun

I've been rereading the Harry Potter series, and I'll probably be done with it within another week or so. My little brother just read Ender's Game for the first time, and was impressed enough by it that I'm itching to read it again (I haven't read it since I was about ten). I need to finish Breakfast of Champions and Dr. Seuss Goes to War, which I abandoned a few weeks ago in favor of homework. I'd like to reread Good Omens and Catch-22 too, and I've never read 1984 or The Color Purple or Zen and the Art of Motorcycle Maintenance or Catcher in the Rye. Those are next in line for me.

What should I read after that?

I'm not looking for a list of good books; I'm looking for that one book that you couldn't put down even after you finished it because your mind was frantically clinging to the ideas in it. Fight Club did that for me. So did The God Eaters and A Prayer for Owen Meany and, when I was younger, Jacob Have I Loved.

What's a book that did that for you?