Books by Jack Kerouak, George Orwell, Salinger, Tom Wolfe, Aldous Huxley, Ray Bradbury, etc.
Apart from the books already mentioned by Ancient Hippy, those I knew in the 1960s were pretty keen on Nabokov and Kafka. There was a lot of interest in Existentialism, too, and in transcendental meditation.
WOW, I didn't know Hippies and Bohemians were related. Which one came from Bohmeia?