Religion Explained is a wonderful discussion of mind and consciousness as well as of religion and its evolutionary origin.  While I'm not certain I agree with all of the author's arguments, I did find his discussion of religion as an artifact of the way our brains are wired for different functions a more plausible and productive approach than that which tries to analyze what religion "does" for its practitioners.  I think that the latter approach was thoroughly done to death over the last century when religion as a cultural behavior finally became a "legal" object of study.