I have too many favorites to list... well, actually, I'll try. What the heck.
Demian by Hermann Hesse-- Amazing story, and while I didn't like Siddhartha, this book is just incredible.
A Scanner Darkly by Philip K. Dick-- One of the trippiest, funniest, darkest looks at life I've ever read. In a word, brilliant. Sadly, though, it makes Do Androids Dream of Electric Sheep seem like a children's book.
Zen in the Art of Writing by Ray Bradbury-- An essential book for writers and, in fact, anyone traversing the wide road of life. Even has some of his little-known poetry in the back.
Great Expectations by Charles Dickens-- An oldie but a goodie. My mom first read this book to me when I was far too young to understand its implications (I was somewhere between 5 and 7). I have read it probably 6 times since, and every time I read it, it both brings back memories and brings new revelations about the story and my life.
On the Road by Jack Kerouac-- This is kind of clicheed, but oh well... I also love The Dharma Bums and Big Sur. On the Road, however, launched my love of travel to new heights.
The Drifters by James Michener-- Echo the love of travel. Throw in an obsession with the 60s.
The Minds of Billy Milligan by Daniel Keyes-- Incredible true story of a man with 24 distinct personalities, beautifully crafted by the author of Flowers for Algernon.
American Psycho by Bret Easton Ellis-- While I must admit I prefer the film version, the book is written in a haphazard, quasi-poetic prose that adds even more insanity to its titular character.
There are plenty more... but who wants to read about me? Ah, whatever...
SD