Diogo recommended me Religulous an humorous documentary about how ridiculous religion is.
Bill Maher interviews some representative people from a few churches and the outcome is funny, yes, but it can’t be taken seriously as a documentary. He never allows his interviewees to finish their ideas and his trying to be funny all the time. In some of them, he’s brilliant, but in overall the movie loses it’s power.
I wouldn’t recommend to anyone who’s certain about their religion. They will (rightfully) criticize the way he interviews people. But if you are doubtful, you might find it funny.