Need roleplaying game

I'm trying to find a game where I can roleplay as a villain or hero like good old superheroes, or even roleplay as a non-superhero character, like a marine, or Master Chief, or Rainbow Dash, whatever. I can't find any online games that have a healthy roleplaying community though. Does anyone know of any multiplayer/online games that have decent roleplaying communities, besides DC Universe Online or Champs Online (my computer can't run those D:)?

I've seen roleplay communities swarming all over the internet... Tumblr, youtube, facebook, etc. Never really bothered to pay attention to them long enough to judge quality though. They're probably anywhere if you look hard enough.