......and I would like a good group of mature gamers to try with.
You pretty much lost us right there.

I've currently been hosting Halo 3 Friday night get-togethers for about six weeks or so, and whenever I start to think interest is starting to wane, we still fill a party to maximum capacity within moments of starting a game. Odds are the Halo 3 Friday Night get-togethers might continue for a little while.
Last night someone expressed disappointment at discovering that my Friends list is full. I'm due to go through and do another "cleaning" (removing people that don't play the same games or who are never online when I am), and when I do you're more than welcome to shoot me an invite. Just be sure to include a quick voice message letting me know who you are or how I know you (GT, OO, or some other way). Some of us have been known to use a profanity or two from time to time........

.......but if you can handle that then you'll find that this is a phenomenal group to play with. Even Harkonis, regardless of how many times he kills you.
On a side note, does anyone know who Lord Polish is? He had to have had a different gamertag and changed it because he's already in my Friends list and I don't recall accepting anyone named "Lord Polish". Just trying to figure out what his previous gamertag was.