I was an ex moderator in one of the most popular forums for gamers: ggc-client.com
This forum was for the gamers who play DOTA. I was moderator in my country region - Macedonia where we have discussions only for DOTA. But, the Lounge section who was definitely the biggest and most active of all. Now that forum is don't exist anymore, because there were a lot changers in that company.
I am now active here, especially in Off Topic and Politics and Society. In most of the forums where there is an Off Topic section people usually post some non-sense threads, but here is very different. People really know what to post and how the get fun.
Politics and Society is the place where I usually want to talk about something serious and if I spend here 2h on 8 threads for example, in Politics and Society I will spend even more.