Unless im playing with friends, i don't bother with my mic. It's funny to hear other people argue however, not worth chipping into though.
[Edited by Vonfuzzball, 2/23/2010 12:10:34 PM]
Thats exactly what I do, only have the mic on if i'm with friends, but then were usually in private chat. And just listen and laugh to the morons insult themselves.
Most common XBL insults i've noticed are Your momma jokes, the ever common "suck my ****" and "your a ***got"
And their stupidity doesn't stop at the pre game lobby either, if you play while actually thinking and not just running and gunning it's quite an easy game to out wit them (for the most part you occasionly get a smart player).