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Atheism and Freethought
By an Amazon.com customer
The InfernovaThe Infernova by S.A. Alenthony
Buy new: $11.66 / Used from: $13.36
An atheist poem, a parody of Dante's Inferno, and a very unique read.
The God DelusionThe God Delusion by Richard Dawkins
Buy used from: $9.24
Already a classic. Addresses all the important arguments as well as it it has ever been done.
The End of Faith: Religion, Terror, and the Future of ReasonThe End of Faith: Religion, Terror, and the Future of Reason by Sam Harris
Buy new: $10.04 / Used from: $1.70
Another modern classic, more of a focus on Islam.
Letter to a Christian Nation (Vintage)Letter to a Christian Nation (Vintage) by Sam Harris
Buy new: $7.92 / Used from: $5.23
Very brief and very, very good, with more focus on Christianity.
The Big Domino in the Sky: And Other Atheistic TalesThe Big Domino in the Sky: And Other Atheistic Tales by Michael Martin
Buy new: $26.98 / Used from: $3.14
Short stories for nonbelievers.
Atheism: The Case Against God (Skeptic's Bookshelf)Atheism: The Case Against God (Skeptic's Bookshelf) by George H. Smith
Buy new: $12.47 / Used from: $2.00
Features a lot of influence from Ayn Rand. A bit more textbook-like than Dawkins. A great reference.
The Science of Good and Evil: Why People Cheat, Gossip, Care, Share, and Follow the Golden RuleThe Science of Good and Evil: Why People Cheat, Gossip, Care, Share, and Follow the Golden Rule by Michael Shermer
Buy new: $11.56 / Used from: $3.60
Fascinating look at the origin of morality. Demonstrates why we don't need to appeal to a supernatural explanation for the existence of a sense of right and wrong. Too bad C.S. Lewis isn't alive to read this.