I found this post made by YOSHIE and I think it's good to share here with you, although apart from Bitcointalk.org and altcoinstalks.com I have never really joined rest forum listed due to personal reason or not fully associated with gambling site that much. Just picking interest gradually from this forum but with time I could tried it out to see it was is.
Bitcointalk is the first real forum experience that some of us have had. I mean, I was on Reddit before, but not as active as I am here in the forum.
Seeing the other list of forums, I will selectively explore some of them to see if they are as organic and with traffic as BitcoinTalk.