If the host is giving you gas just run for your life. For all you know he'll slap your config around because he doesn't like one of the attacks you use. If he boots somebody else in the room that you know doesn't deserve the boot, he's probably going to come after somebody else he doesn't like next. Besides, an empty room is an unhappy admin, so strike back by just getting out of there.
Personally (and this is just me tooting my horn) I've only run into a few people who can beat me consistently (or most of the time anyway), either with beams or melee, and that number is dwindling. 99 / 100 times, the guy insulting and mocking me is not as good as I am, so I don't have a problem being light hearted or gently sarcastic back to them. You know the drill...
"haha u lame f4g I pwnxor3d u"
"My oh my. Just wait until my boyfriend gets here."
"lmao you g4y 4ss"
"I sure am, and you should try it. Nothing beats a little man on man with a friend from ESF."
You know... after pulling an act like that for a while the guy gets hopelessly confused and gives up. It's always fun to watch him run out of things to say and then start insulting my playing style.
The other thing I do is just beat them... over... and over... and over and over and over and over and over. Most of you foolios out there get off about 1 kill over 12 deaths with me. If you're lucky it's more like 3 to 2, but I come out on top almost every time. And you're right, they will chase you around for the rest of the game because they're angry, but if they can't beat you, they can't brag. Oh, they'll resort to something else, like saying "it must suck not having any friends" or "at least i don't live on this game," but it's just because they've been so soundly defeated that they have lost all previous bragging rights. I'd say it's the easiest and the most fun revenge you can have against a weaker player who is really getting on your nerves.