xenocrash

I voted for timed, but my real answer is:
D) Timed escort missions
 
I finally played through Crysis and the worst part was an escort mission where your buddy's health is constantly running down and can only be increased by going to specific spots on the map.

RTS (and to a lesser exent TBS)
FIghting Games 
 
Games I suck at, but DON'T play anyway:
Adventure Games (I'm just not patient/insane enough to figure out the item combinations)