Books on Religion
 

I'm looking for recommendations for books about religion. Specifically, books that either argue for or against religion, like The God Delusion or Mere Christianity. I don't care if they're old or new, I'd just like them to have an argument either way.

Thanks.

Breaking the Spell is a nice, cool-headed book about religion from an atheist perspective. I love The God Delusion, but while that book contests against religion with very good arguments, Breaking the Spell already assumes that there's something iffy about religion and observes it as a "Natural Phenomenon"

Also, I wouldn't be me if I didn't recommend God and the State by Mikhail Bakunin.