The Selfish Gene is not about selfishness
On The Selfish Gene by Richard Dawkins
The title has misled people for decades, and Dawkins has said himself that he might have picked a different one. It isn't saying we should be selfish. It says that looking at evolution from the gene's point of view explains odd things, including why animals are sometimes kind to each other.
It's old now, but the writing is clear and the game theory chapter is a real pleasure. Also, this is the book where the word meme comes from, in case you need a fact for your next dinner.