This religious bitch in "The Mist". If she had been in face of me, muttering her nonsense, I'm pretty sure I would have flung my fists at her face until her head looked like a messy, bloody mess.
Wait, over the Internet? Well, once I get on Youtube, I become a full-fledged troll, making random people mad with all my might. But I'm a classy troll. The trick is to keep using your intelligence against the victim's stupidity. Don't let any mistake, grammatical error, historical fault pass, use them all to destroy any credibility, dignity, or smartness he may have. Also, be a total douchebag. Mention his dysfunctional family as much as possible, as well as his weight problems and the death of his pets. Also, if he says his mom is dead, you know what to do, right?
TL;DR, I'm usually the one that people want to punch over the Internet. I actually received at least two dozens of death threats over my trolling career on Youtube.
But no worries, as soon as I'm out of my hunting grounds, I come back to the nice, helpful and tolerant person I usually am :)