Good things about AT forums:
Moderators - they keep things from degenerating into a huge pile of useless and offensive crap and neffing. As much as people don't like being told what they cannot post, it is much better than what happens on less moderated forums (check out offtopic.com if you want to see how bad it can get)
Number of active members - unlike some forums, there are enough people here so there are always new topics and always someone willing to give advice. Some forums, you can post a question and wait a week before someone ever responds.
Variety of people - Always someone to make me laugh, have friendly discussion with, or share expertise.