Good/bad gameplay mechanics

[Arkuni]

What gameplay mechanics are good/bad in your opinion and why?

A Jedi's favorite:
The push plasmid in Bioshock. I simply love smashing living ragdolls over furniture and stuff. Quite frankly, the Jedi Knight games missed the furniture.

One of the stupidest mechanics in the god damn universe!:
The car stealing mini-game in GTA:Chinatown. The intense escape from a billion cops grinds to a halt when you decide to flee in a parked car.

 

[Souplex]

Good: Castlevanias exploration platforming.
Bad: Castlevanias leveling up; you can always just grind and overpower your foes if you lack the skill.

 

[GreyWolf257]

Worst: The fighting system in the S.T.A.L.K.E.R games (but I still like them. Go figure)

Best: Oblivion's super-free-roaming style of gameplay (Please God, let Bethesda create another Elder Scrolls game!)