Pre 2011 Homestuck Fandom was pretty rad. It didn't last though. It seems a lot better now though that the webcomic has ended and there's less of a hype train surrounding it.

A fandom I've always disliked is that portion of the Undertale fandom that were all "If you don't play the game this way your playing it WRONG and you should feel BAD". I loved Undertale, and I would always recommend the Pacifist route, but if people want to play the Genocide route that just let them. They paid the 10 bucks, they can play the game how they want.