Fantasy: The Inheritance Trilogy (Eragon, Eldest, Brisingr) with the final novel yet to come. I enjoyed these even more than The Lord Of The Rings. No matter what, do NOT see the Eragon movie! That movie was absolutely horrible and a complete travesty of the book.
Fiction/Spiritual: +1 for Siddhartha by Herman Hesse. I also recommend Journey To The East by Hesse.
Non-fiction/Spiritual: The Spiritwalker trilogy by Hank Wesselman, Om Baba: A Mystical Odyssey by Tom Heckel, Letters From The Afterlife by Elsa Barker, Testimony of Light by Helen Greaves.
Fiction: George Orwell's Nineteen Eighty Four, Aldous Huxley's A Brave New World
Non-fiction/Philosophy: books by Jiddu Krishnamurti and Eckhart Tolle
Also, plus 1 to Atlas Shrugged, Isaac Asimov's robot series, George Orwell's Animal Farm and the works of Kurt Vonnegut.