So, I'm posting here cause I'd like to share some new systems I've found. First of all, there's Wushu here. It's very cool, and it's defining feature is pretty much that what the players say happens, really happens. The player doesn't just try to hit the boss, he hits the boss. Another big feature of the game is that the way the dice function. They resolve a scene, not a single action. You don't roll to see if you open the lock on the door. You roll to move the scene along, and if part of that is you describing how you open the door with illicit means, then that's what happens.
Second of all is a game called Prime Time Adventures or PTA and it's all about modeling the interactions of a group of players to duplicate the style of a typical television show. It's really hard to describe how it works in play, but it also is focused around the idea that the roll isn't to determine if a character succeeds or fails at a single action, but wether or not they make progress towards dealing with their own agenda or issue.
Needless to say, both of these games really rely very heavily on the trust of your group. If your group has trust issues, or the players like to be jerks, then the game will self destruct in short order. I've found that at least with most groups, simply talking about those issues before play even starts will really help up the level of maturity. If you expect great things from your players, they will provide them in abundance.