well, let's see. i check 4 forums on a regular basis, including here... and i check another 30 or so on an infrequent basis, and i keep tabs on about 25 yahoo groups aside from the above. ^^
but since the poll was for active forums, i voted 4-5.
in case anyone was curious, here are the other three:
oolite, fun with retro gaming
gametable, simple straightforward shared whiteboard java program for online rpg with real-time maps and dice.
epic orb of the dungeonmaster +10 (dm/player all-in-one util for d20) lite version is cross-platform....
hope you find the programs useful! =D