This is a question that is unanswerable. There is no way to actually count all of this, so I can only give a wild guess. I'd say about 2-3 thousand people go on this site at least once a week.
I would guess an estimate of 5,000 that show themselves to the public (i.e. profile comments, game comments, forum posts). Probably 10,000 that play games. maybe 30,000 overall that play on once every 2 weeks.
see, THIS is why it would be good to add a search onto the main engine for members. If you find an admin or mod, tell him I said that.
But as of an ACTIVE LIST, just find out who is really low (say, go to EvilDogs aaccount) and find out what number he is out of the 99,000 people here. It won't be accurate to say the least, but you'll get a good idea, because he submitted a game.