sc: most of what the siege tank says, especially the song XD
R:TW: basicly everything, even "onagars!"
battle realms: "hot, like FIRE" alchemist... never used that unit, but I still loved it...
and if it counts: "our priest has been immobilized!"
giant cookie if you know where its from
EDIT: cant freaking believe I forgot my favorite...
red alert 2: "HAHAhahaha"... god damnit tanya was awesome...
I even do it myself in halo 2 when using duel pistols, just for the heck of it (I usually die, but thats not the point)