Just finished Abraham's Curse, the Roots of Violence in Judaism, CHristianity, and Islam, by Bruce Chilton. Currently reading Gospel Truth, by Russell Shorto, on the search for the historic Jesus. My friend, Brother Robert, a Carmelite Friar, told me about Practicing the Presence of God, by Brother Lawrence (available online for free), and it has altered how I view my day to day life. Bro. Robert also sent me Centering Prayer and Inner Awakening, by Cynthia Bourgeault.
I would recommend Reinhold Niebuhr's The Irony of American History, and Andrew Bacevich's The Limits of Power, The End of American Exceptionalism as must read books for any thinking American.
Peter Rollins is a young Irish author, theologian, and philosopher. His books, Faith Beyond Belief, The Fidelity of Betrayal, and The Orthodox Heretic, have all been mind expanding for me.
Other must reads include anything by Bishop John Shelby Spong, A Generous Orthodoxy, by Brian McLaren, and Leslie Weatherhead's, Christian Agnostic. I also read the Bible daily, and frequently use gnostic writings for contemplative thought. Some of the best teachings of Jesus appear in the Gospel of Thomas, The Gospel of Philip, and The Gospel of Truth.
For fiction, I read a lot of mystery/detective stuff by James Lee Burke, and everything by Chuck Palahnuik (Fight Club and many others)