I found this great article. It's rather long but a good read for anyone interested.
The 10 bullet points are:-
1) Spirituality for dummies
2) Loss of spiritual depth perception
3) Engineered obedience training
4) Toilet-bowl time management
5) Support your local pedophile
6) Incest is best
7) Idiocy or hypocrisy- pick one
8) Inherited falsehood
9) Compassion in chains
10) Faith is fear
http://www.stevepavlina.com/blog/2008/05/10-reasons-you-should-never-have-a-religion/