I want to know which go club in the US has the most active members. I'm trying to find a club that I could go to every day and expect to play a game or two. If possible I'd like it to be a club that has it's own building or private room.

I play at the Seattle Go Center which is pretty nice and can't recommend it enough.

I've heard Feng Yun Go School is the biggest AGA chapter and probably the best organized Go learning environment in the country.

After that I would put the San Francisco bay area. I lived there, but the problem is that the sprawl of the area I was in tended to make head to head games be the monthly tournaments since otherwise you have to drive long distances. Mingjiu at the time was helping run a club in Menlo Park and even with a professional there, the weekly meetings only had four people show up.