Reading Fight Club is just as amazing as the movie. I would definitely recommend that.
Tao of Pooh and Ishmael are also life changers.
Anything by Dennis Lehane; Shutter Island, Gone baby Gone, Mystic River... Or Cormac McCarthy; The ROad, No Country For Old Men.
Zen and The Art of Motorcycle Maintenance is pretty heavy but if you can get through it its worth it.