My friends and I had some ideas for cinematic fighting although limited mostly for melee characters. When a critical is confirmed depending on the nature of the enemy, the PC roll some skill or ability checks like quick-time events. Let me give you an example. The Giant is under half his Hit Points. A fighter next to it makes an attack roll and it's 20 and then he confirms it.
Provided the Giant is not slayed outright, the Fighter can use up an action point (yes, we use action points, too) and make for example a Jump skill check followed by a Balance check and then an attack roll. This means that the player, after the critical manages to jump up on the giant, keep his balance and then make a lethal attack. The attack gets a bunch of extra damage depending on the Jump and Balance rolls and the player is awarded. Thing is that the control of the scene is given to the DM's imagination and very exciting cinematic battles can be created.
Well, mostly this is cheesy and does not enhance the game in other ways, whatsoever.
PS. An example of a Jackie Chan monk would be to move a certain distance and attack many opponents but making a lot of checks and taking - to damage.