I'm almost done reading this great book by Christopher Hitchens. The only thing keeping me from finishing it is, having to read stuff for my classes. You can guaran-damn-tee that Hitchens puts forth a tremendous argument against religion. He is able to point out the many fallacies within religion and so forth.
Pick it up at your local bookstore or check it out at your library.
god is not Great: How Religion Poisons Everything. Christopher Hitchens. 2007