I'm lucky I guess, I don't meet a lot of em. I usually just let them tire themselves out. Hey, THEY are the ones that look dumb. It's funny how stupid people can be.
If I'm the tank tho, and they're really morons and their crap gets to other people in the group, I just might egg em on and get them REALLY riled up. Also funny. I imagine them after the dungeon's over, still pissed off and cussing me, telling all their assholes friends how they just did a dungeon with stupid morons and going on and on... while the rest of us move on with our lives and forget they even existed, except maybe for the camp fire stories XD