Life, the Universe and Everything (Hitchhiker's Trilogy (Paperback))
This is another brilliant work by Adams. One of my favorite parts is an encounter between Dent and a creature named Arajag whose various reincarnated forms Arthur has reputedly murdered over and over.
"What have you got against me, Dent?" snarled the creature, advancing on him in a painful waddle.
"Nothing," insisted Arthur, "honestly, nothing."
"Seems a strange way to relate to somebody you've got nothing against, killing them all the time. Very curious piece of social interaction, I would call that. I'd also call it a lie!"
This series of books is one that can be enjoyed by sci-fi lovers and non-sci-fi lovers alike. Layered with a remarkable sci-fi storyline and a hilarious social commentary, this is a story anyone can love.