Methinks not only in the tongue of English, but also in the Chinese forums, I shall but browse or be a silent poster at best, and rarely shall I participate in some discussions.
That's part of the 4chan's charm: the qualities of these discussion can range from complete shitposting to valuable conversations about some niche stuff. I mainly browse vidya boards so I think the same works for /a/.
For me it was 4chan /a/ and /b/ and /lit/ I followed a specific anime/manga, browsed for months,
and summed up the regular part: a has too many shitposts, and one of my favorite manga has been frantically disparaged and notorious, but I have also seen many deep-rooted and heartfelt gold comments, which can be described as a double-edged sword, and I am not interested in anything other than the anime/manga I follow.
B-random is completely, full of pornography, logshit, kik, loli/shota, bbc、rekt, and occasionally interesting threads.
At tvtime.com, you can find discussions about not only anime, but also movies and a wide variety of TV shows. The site is a place to active discussions about every episode.
/c/ /g/ board is my fav, sometimes e d vg vt