Wanna use Samus with the Zero Suit in Super Smash Bros. Brawl? There is a code you can enter to to unlock it.
Choose Samus on the character screen and hold the following button before the match starts for the controller that is being used:
Gamecube or Classic controller – Hold down the R button.
Wii-mote with Nunchuk – Hold down the Z button.
Wii-mote – Hold the Minus (-) button.