It really depends on what you're looking for. If you're into reading anime reviews, @Nanashi has a bunch of great ones in the Anime & Manga reviews and reccomendations section. If you watch anime seasonally as it come out, I'm doing a set of reviews for each episode in the writers forum. There's also the weekly Lewd News which @Senpai compiles from articles made by a bunch of the people here. Its always an awesome read.
Those are kind of the main forums I watch, but there's great stuff everywhere. Depend's on your interests as I said.
A good place to look for active threads is in the unread posts thing that you can see at the top of the page. Also, there's a Discord server and an IRC server , the info of which can be found in the meta forum. They're pretty chill places to hang out.