I'm checking out Kbin, Squabbles and Tildes (from the outside, waiting for an invite). I think Kbin is my favorite so far, because I don't need to log in to Mastodon or Lemmy to get content from there, and because we can downvote stuff. Also, promoting decentralized sites seems appropriate after all the drama around Reddit, Twitter, Facebook etc.
I really like Squabbles' design though, I'll keep checking it out, maybe both sites will evolve into something unique given some time.