As Lemmy starts maturing, there starts being so many communities out there that it's pretty hard to keep track. I've been browsing for about a month now, here's a list of popular communities I've subscribed to that others would find interesting!
Not many of these were noticeable while browsing communities so you may have missed some of these. I've roughly ranked these based on which I'd spend the most time on in each category.
Also note that I would add Kbin communities as well, but federation between Lemmy and Kbin is still not working well, so right now this post is for Lemmy communities only!
Nah the pending thing is a known issue. It's essentially a visual bug and you are subscribed and will see those communities in your feed, but the UI doesn't update for whatever reason. Seen some reports that you can fix it by repeatedly unsubbing and trying again, but it shouldn't affect the actual functioning.
(fun fact there is no such thing as "approving" community members even though that's what this totally looks like it is!)