Most people have maphack. I dont think cannon rush will work. Here is what i think for fastest no rule:
terran: build marine or bat combine with medic or build vulture
protoss: build a lot of zealots
zerg: ling rush
Most of the time this units rock unless u are facing a pro.
With stacked hydra you can get 200 of them in the same spot.
So all the hydras just blast at once, killing almost all the goons quickly while the goons need to wait for the ones ahead to die so they can move up and thus deal less damage.