I visit one genealogy forum, regularly, and others from time to time. I've joined an English lit forum, but can't even remember its name.
I used to be very involved in a local history forum, until it closed down. The owner found that it was just too much worry, to deal with trolls, vulgarity, insults, etc.
I visit lots of non-forum sites for information, etc.
This, of course, is the forum I visit most often.
Most of the time I enjoy it, but sometimes it can get a bit fraught.