nostr:npub19lt4284mghqxekzm6n5njxurnxrxhqhrva2leusdsuu5ja5jeycq66qfjk I have accounts with a number of instances, but use Lemmy.world the most. It is huge, growing and can sometimes be unstable, but the devs seem committed to making it the best. Lemdro.id is a good newer instance that seems well run. Beehaw.org is a good instance that has a more sanitized philosophy (only select communities, no down voting and a lot less NSFW content).

For Kbin, I believe Kbin.social is the way to go. I was also using reddit.buzz which is shutting down (maybe the one you are referring to?)