Toribash - Violence Perfected
Toribash is a free, downloadable ragdoll-based fighting game, and it's pretty fun once you've got the hang of it. The tutorials are poor and don't really explain things all that well, so it's fucking difficult when you first start, so just experiment around in free play. Here's a video of some of the stuff you can do when you're pro at the single player mode:
Multiplayer is what I love playing the most, it's 1v1, you can set up your own servers, and the mods are incredibly simple to apply. Some of my favourite modes include aikido, sumo, and twinswords. Fucking fun shit right there, know what I mean son?
Basically, you contract/extend/relax/hold different muscles of the body to make your ragdoll do cool stuff. In free play, when you press Space you advance 10 frames, where the game pauses and you can adjust your ragdoll. In multiplayer it's usually about 30 frames so the game flows a bit better, but there's a time limit on which joints/muscles you interact with, as opposed to pressing Space.
It's fucking fun, and it's fucking free, so download it you BITCH!