What happens after death for an Atheist?
Well, the same thing that happens to the rest of us. Whether a person believes in God or not will not change if God exists. As a christian, I really hope that Christianity is the right religion, and that I don't get any surprises in the after-life line-up to be judged. However, I could be wrong, the right religion could be another one, or there may be no god, but whatever I believe to be true has no bearing on what is. Athiests will undergo judgement just like everybody else. I understand this is a pretty lame answer, but a restatement of the topic is kind of needed: What happens after death if there is no God?
Well, then, I just have no idea.