This is stupid and amazing and kind of addictinghttp://www.saltybet.com/
or if you just want to watch the Twitch stream http://www.twitch.tv/saltybet
Oh, and it's all fake money, of course.
And if you don't know what MUGEN is, it's a fighting engine where the community makes the characters, so basically ripoffs from every other fighting game, but also every anime, or cartoon or what have you. So if you ever wanted to see Iron Man fight Winnie the Pooh, or Goku fight Pikachu, this has it.