I look in on the main national forum, Diamonds & Tuxedoes, and Another Realm fairly often. The main forum has some fun stuff and occasionally some good information. Threads go off-topic frequently and tend to degenerate into flirting, but flirting is fun sometimes. D & T is a bit cliquish and those of us who aren't among the half-dozen or so regulars can get bashed pretty easily, but their bickering is usually civil and sometimes creative, so there's entertainment value. Another Realm has a lot of interesting stuff for those with tastes that are a bit...eclectic. I've found some links to wonderful toy and equipment suppliers there.
I avoid the National Sandbox and National Mens' Lounge--dominated by arrogant Texans who think "fucktard" is a masterful insult.