999%

Description
This is a glitch in Super Smash Bros (yes, the original) that performs 999% damage on your opponent. The first step is to choose Mario as your character. The second step is to pick a safe stage (such as Kongo Jungle). Get close to the middle of the stage by pushing your opponent. Now, get as close as possible to him. Press start and go to the items and look for green shells. Put as many as you can (until you hear the beep). Now, use Mario's tornado move, and both characters will freeze, sparks will fly, and your opponent's damage should shoot up to 999% in a matter of seconds. This effect ends when the shells disappear.

Trivia

 * This can be done with (if there’s) BLUE shells, but you will be damaged, too, and you both will get blasted out before you take 999 %.
 * This glitch was fixed in Super Smash Bros Melee, as you cannot stack multiple shells on top of one another. (but you can place a lot more at once.)
 * This can also be done on other stages. For example. on the Mushroom Kingdom stage, choosing Samus, and using Up+B in between the shells and the other character, which causes the same glitch.