If you want biggest general forum then the answer is www.offtopic.com www.somethingawful.com would be next in line Gaia is the largest forum, but it is no longer just a forum it is a role playing game, virtual currency hang-out for anime freaks. One of my forums www.genmay.com is #34 for English language forums on bog-boards.
see http://www.gaiaonline.com/forum Who is Online? - 45259 users. (41606 visible, 3221 hidden, 432 guests). Gaia has 1,725,025,210 articles posted with 21,005,892 registered users. Most users ever online was 123,381 on Tue Apr 01, 2008 5:44 pm but some french forums such as http://forum.doctissimo.fr/ have are numerous times more busy than offtopic.com Nombre total de messages : 175,473,164 Membres Enregistrés : 2124264 http://www.forum-auto.com/ Nombre total de messages : 41,624,873 Membres Enregistrés : 784701