Keep the Aspidistra Flying - George Orwell
The Outsider - Albert Camus
The Illuminatus Trilogy - Robert Shea and Robert Anton Wilson
Zen and the Art of Motorcycle Maintenance - Robert Pirsig
Catch-22 - Joseph Heller
Unreliable Memoirs - Clive James
Consciousness Explained - Daniel C Dennett
Those are all books that seemed important to me at the time, but which probably didn't have a lasting real effect.
The books which made me love reading are probably more significant, but I can't really remember what those were.