although he loses points for the unoriginal title*

Best argument in support of atheism I've come across as of yet: Defenders of the Faith. Perhaps because Zizek makes no attempt to disprove the existence of G-d. That being said, it's still a largely flawed argument, but I won't ruin the fun by pointing out the weak spots.

The opening paragraph:

FOR centuries, we have been told that without religion we are no more than egotistic animals fighting for our share, our only morality that of a pack of wolves; only religion, it is said, can elevate us to a higher spiritual level. Today, when religion is emerging as the wellspring of murderous violence around the world, assurances that Christian or Muslim or Hindu fundamentalists are only abusing and perverting the noble spiritual messages of their creeds ring increasingly hollow. What about restoring the dignity of atheism, one of Europe's greatest legacies and perhaps our only chance for peace?

*"Defender of the Faith," short story by Phillip Roth (p. 1960)