The Halo Trilogy, The Giver, Gathering Blue, and the Messenger (unamed trilogy), and the Lord of the Rings complete with the Book of Lost Tales 1 and 2 and the Silmarilion. The last three I've never actually finished though. :">
A lot of my favorite books I don't acually own, but have read at school. Those include Walk Two Moons and the True Confessions of Charlotte Doyle.
Oh yeah, and all my brother's college textbooks he doesn't need anymore. Mostly programming stuff. I'm not very far into those yet.