As a counterbalance I'm going to throw this out:
The zealously atheist, they're like some sort of unholy combination (haha, I crack myself up) of religious nutjob and conspiracy theorist. And they're generally really, really stupid; like don't actually understand history, politics, the religion they hate (usually Catholicism), the religions that have nothing to do with the religion they hate, or science for that matter.
Semnae is (was?) a good example. Didn't understand that not all religions are the same, not all religious people want to convert him, didn't understand that "string theory" was actually nothing more than a loose collection of semi-related internally consistent mathematical models, etc.