The Hitch Hiker's Guide to the Galaxy
A truly funny bit of philosophical sci-fi. I was introduced to this book through the film that came out while I was in high school. I was pleasantly surprised to find how much of the movie was lifted from the first half of the book.
My favorite reference to this book is from Billy Wood's track Checkpoints:
Whitey finally in that spaceship like "So long, and thanks for all the fish!"
Adams, Douglas. The Hitch Hiker's Guide to the Galaxy. London: Pan Books, 1979. Printed Book330-25864-8.