Thanks for thinking of the OP's criteria in this. Unfortunately, I couldn't get past the intro where they're mocking some prankster who is traumatizing children by pretending to set their house on fire while their parents stand outside and watch. It was too much for me to stomach. Thanks for the rest of your great list as well. I've heard of some of them. It's quite an eclectic list.h3h3productions / Ethan and Hila - The first one: in which some guy (Ethan) mocks YouTube videos. The second one: the alternate channel, which also has Hila who is usually behind the camera for the former. YouTube goofs and gaffes. Not exactly highbrow and sometimes offensive but funny. They seem to be softening up lately, I think they are starting to get disillusioned with the number of similar channels who take it all way way too far. This definitely fulfils your first criterion, OP. There is a community and a subreddit and lots of in-jokes. Probably overlaps a bit with 4chan users as well, so beware.