At the moment, most people can commonly agree that melee combat in games is not what it could be.
I've played my fair share of melee combat games ranging from Dynasty Warriors to Oblivion, frankly I've only played one game that had a combat system that felt like it worked on a scale of realism.
I'm coming from the standpoint of a seasoned veteran of martial arts and military background, and games are really just hack and slashes - though are getting better and better as we master and insert more and more motion cap into games.
Regardless, awesome looking melee between two characters is usually two preset motions cap animations that are set in space, and each character can't move out of that space. Meaning it's linear and has no freedom of movement. You could have something like AC or AC2 with their 'X to kill' system, though that makes the game a fully functional line up and die method or people who have a good finger. Then you have complete freedom which turns into Oblivion where the player moves around like they have helium balloons attached to their feet.
None of these essentially harness the true aspects of combat. Looking for ideas here that incorporate thinking systems that render movements based on rules (much like Ai does). Combat really involves, stability, footwork, and speed.