Reddit would be my most used. Although you don't really get to know the members like you would on this site, it's super easy to find and explore content on a topic. It's definitely got its downsides, but I enjoy using it.
It really does seem that Facebook, Reddit, and discord, have all but killed most forums like this one. I think it's kind of sad. Forums used to be so active.
bumping this thread cuz i'd really like to check out some new places! i feel like cozy semi-active / active forums are pretty hidden. TBT is definitely my most used one, but here's a few others i've been on:
https://forums.bulbagarden.net/index.php - pokemon forum, probably the next most active thing i've used. i don't talk on there too often but i read through threads when i'm bored! my only nitpick is that none of the site themes feel very easy on my eyes. maybe i just need to pick one and get used to it
https://squidboards.com/ - splatoon forum, used to seem like a nice welcoming place but every time i visit lately it's completely overrun with bots. there's like, 4 people online a day. lots of the staff have been offline for a long time. it's a shame, no idea why it's barely taken care of these days
https://www.tamatalk.com/ - tamagotchi forum, nice to peruse but also pretty inactive. not much to say about this one
I actively use this forum, as well as Animal Crossing Community. I’ve deleted most social media. I only use Snapchat, Instagram, and YouTube, in terms of social media. I prefer forums, though.
I’m a moderator on the Lake Valor Pokémon forums. I don’t use the site more than a few times a week, but I regularly keep an eye on the Discord. We’re no where near as popular as we used to be sadly.
I use Tumblr as Neb63 and Twitter as Neb633. Thankfully I don’t check these social media sites nearly as much as I used to. It was an unhealthy habit.
I also use Anilist to log my anime and manga consumption. Sometimes I use the forum, but for the most part I just use it for logging purposes. The statistics page is fun to look at!
I occasionally browse through the Zelda Dungeon Forum! ^^ (It has walkthroughs of every Zelda game that I continuously check because I literally suck at playing Zelda, haha.) I also use Discord and Quotev.