If I happen to be the admin of the site, and 'what I say goes' i'll troll them back like they've never been trolled before. I'll sit there for an hour fighting with them until they either get bored and leave, or epic fail themselves. At that point i'll just ban them, or I might let them stay a member depending on how good of a troll they were (I only want high quality trolls on my site). This usually only applies to BlueHumor.org
Now if i'm not the admin, like here, then you have to do the whole 'be nice' thing, send them a PM, delete their topics, give them a warning, ect.
I'm sure that's because you have quite a handful of topics that stir large debates and high emotions within people, which can be both a blessing and a scar. The good side is, you'll never run out of things to chat off about, but the down side is that you're going to get a million and 4 (yes, FOUR) trolls, wanting everyone to think like their own beliefs ~wink~