Super Smash Bros. Glitches

999% easily
Go to training mode and pick either Mario, Luigi or Samus and choose any opponent and choose Peaches castle as the map. Go to the menu screen and get 4 green shells next to the enemy. Then use the following moves for each character:

Mario: Mario Tornado
Luigi: Luigi Cyclone
Samus: Screw attack

P.S. For Samus you have to be under them to work