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.
Never! And you can't also compares bitcointalk.org to them because their operation and terms of service aren't that original like bitcointalk, I mean there are no much traffic over them, although I can't fully say as the only forum I have used is altcoinstalks which is not also comparable to bitcointalk.org. And yes, I started from social app before finding my way here and I have loved to use this forum than any other social app.