I have joined just about every one out there I think lol, but overall I post little. Rimfirecentral and SigForum are my favorites other than here. Others I primarly read or go to when I am looking at a particular firearm. But I sure have an extensive favorites list!
I like warrifles.com and sigforum.com every once in a while. If I have a specific sig question I will go to sigforum. Like finding out about the new X-6!
Lightfighter.net its almost all military, front line and training, 1st line weapons comparisons, gear whats good and bad and the team room is interesting, otherwise about 90% here
i spend way too much time on here, but that is only recently.
I'm also on:
thehighroad.us (DOT US!!!!)
thefiringline.com
I'm a big fan of rimfirecentral.com and nitroexpress.com but i'm not a member of those, i just go and read. I also on a bunch of car forums.