D6, Storyteller, and Shadowrun have already been mentioned.
Traveller 4 "Marc Miller's Traveller" uses a sort of backwards system that rolls dice for difficulty and compares it to a skill/ability target number.
EABA (oh how the mighty have fallen)
Over the Edge
Silhouette
Sorcerer
LUG Star Trek
There were dozens of variants of the mechanic in the flurry of excrable little games that popped up like hives in the wake of Vampire.