Whenever I cast Humongofrog, I always say "Froggy is Sick :P" and when someone else casts Stormzilla I always say "Go Barney Go!" One time when i used Minotaur on some guy he said: "Hey Big Guy" then "LOVE the belt" everyone started laughing.
There's one i forgot (I took this from my friend Nichalos DarkFlame so give some credit to him). Here it is: SON OF A STORM WIZARD! Thats what we say when my tempest or wild bold scores a couple grand in damage.