As an atheist: Maher is not someone who argues with integrity. Religulous is a perfect example of this.
Has an interview with a Rabbi who's anti-Israel. The implication is that you should be pro-Israel by default, and if you don't agree it's some aberrant position that needs to be justified like saying the Earth is flat. This is extremely hypocritical for a movie that's all about mocking religious shit when that's exactly what Israel is based on.