Covering as the whole city in gold piles, problem was they disappeared after a while... quite disappointing.
Starcraft: building an armada of command centres trying to cover the opponents buildings so he can't select them.
Lords of the realm 2: attacking with as many 50 peasant armies as possible burning every single one of the opponents fields.
And of course burning the quarry and the black smith.
Doomlegacy: Changing the corpse sprite to a normal sprite, then hiding in the jungle of your own corpes plasmaing the opponent to death.
My buddy used to play as a box, Now THAT is annoying.