** Updated - February 27, 2014 **
Alright... I've gone through and cleaned up the thread, checked the links, removed dead ones, and redirected several others. Feel free to submit additional suggestions. I have to believe that most teams have
some sort of equivalent forums to WSI. Generally, the forums that I am not happy with are: TB, CLE, and COL (and NYYFans is currently down, but I think that is only a temporary issue).
I also tend to think that LAD, LAA, NYY and SF have a bigger internet presence than I have listed. For instance, if you go to the PRO SPORTS DAILY site, those teams have monster boards there. ... So, if you know of any team forums that draw a ton of traffic, please let me know and I'll work them in.