On the Road, Dharma Bums, Lonesome Traveler (Kerouac); A Farewell to Arms (Hemingway); The Great Shark Hunt (Thompson), Zen/Art Motorcycle Maintenance (Pirsig), Siddhartha (Hesse), Bible.
Probably more but that's all I can think of. Not all have influenced in the sense that I read them and their entire contents changed my life, sometimes it was just a paragraph or it was just that that book happened to be part of an otherwise significant event.