I have a couple:

- who created god?
- if you religous people really know so much more than atheists, then why are you always wrong?
- if god really does exist, why would he want his believers brainwashed to obey all authority and start endless bloodshed whenever their leaders want to? If he really does want this, god sucks. But if he doesn't, then all you religous people are just pissing god off and only the atheists please him.

Sorry for the exaggerations and generalizations, I'm just trying to prove a point.