Gah, what game was it... it was an old game for the GBA... something with Dragonball Z...
I forget the name of the game, but you had the power to fly around in that game, and if something hit you with a ki blast, you landed and for some reason became 100% invincible (repeatable). Made boss fights very easy if you didn't feel like a challenge.
Also, in SSBM, an apple exploded when it flew out of the tree in Dream Land. I have no idea if it's even a glitch (it is Smash Bros, after all), but sure made me and a friend laugh.