If your looking to get away from the negativity most forums seem to have these days, play in tournaments, or share you work then join http://TalkHalo.net/
Were also having a montage competition at the moment. You can submit two montages per person from any Halo game. All montages must be submitted by the 1st of February. http://talkhalo.net/viewtopic.php?f=5&t=162