10 kick ass action game mechanics

So i bought a whole eff-ton of games from Steam over xmas, and getting to play some gems for the first time. A standout is Just Cause, which is frankly some of the most hilarious retardation i have ever seen. This is a good thing, and has me totally excited about JC2. It got me thinking about how a core game mechanic can really drive a game, in this case the hijacking/stunt position/parachute trifecta. Here's a list of mechanics i really enjoy in action games; Any combination of these will likely get me interested. All 10 might make me implode.

  1. Jumping from one moving vehicle to another
    Ever since Pursuit Force (though this is probably not the first instance of it), I've found this stuff totally awesome. It's just really satisfying to pull off. Needs slow-mo, and mid-air shooting of driver heads is a definite plus.
  2. Delayed homing missile lock-on
    Been playing a bunch of Warhawk recently, and the #1 thing that really keeps me coming back is the near constant delayed-lock reactions. There's something almost Hitchcock about it. A bomb under a desk that goes off is action. A bomb under a desk that hasn't gone off is suspense. There's something great about trying to maintain a lock until you can really nail someone. The louder and more annoying the lock on klaxon the better.
  3. Hi-Fi climbing
    Infamous, Assassins Creed and The Saboteur all do this. I'm not sure which i prefer, but I'm pretty sure it's all awesome.
  4. Grappling hook
    Kind of begins and ends with Bionic Commando this, but then again that whole game was defined by it. Curious about how Just Cause 2 is going to roll with it, but the more physical and momentum based it is, the better. God damn i love swinging from shit!
  5. Music-sync rewards
    You don't see this often in action games that aren't dedicated rhythm-action titles, and that surprises me somewhat. Music is such a big part of getting adrenaline going in a tight action sequence, and rewarding players for "playing along" seems like a total nobrainer. Might not be of course. But hey!
  6. Flying kick
    It's just neat to jump and kick at things. What can i say?
  7. Move charging
    Hulk: Ultimate Destruction and Prototype both do this, and it's freaking awesome. Every single move in a fighting game should be chargeable, complete with slow-mo during charge. It's especially important for the jump to be chargeable.
  8. Skill trees
    A wide, well developed skill tree is a big part of what keeps me coming back to action RPGs. There's something neat about working your way to a target spec, gaining other rewards along the way.
  9. Property acquisition and management
    I was heartbroken to see GTA4 omit the property ownership nonsense of San Andreas. Might be the completist in me, but unless i actually own the world, I'm not satisfied (!!!11)
  10. Strategic dismemberment
    This can take a bunch of forms. For me it didn't start with Dead Space, but rather Mechwarrior, where plucking off weapons or limbs was completely vital to success. The idea of taking an enemy apart weapon by weapon to turn the battle in your favor feels much more resonant than just shooting people in the face. Though that is pretty neat too.
Anyone else got favorite mechanics that really get them going? The more obscure the better!