Super Smash Bros. Brawl Codes -

Unlock Characters
Lucario - Defeat in SSE with Meta Knight
Luigi - Complete Classic Mode on Easy
Captain Falcon - Beat Classic in 20 minutes or less then defeat him in the following match
Jigglypuff - Complete Classic Mode with any character other than Ike or Complete Event Match 20
Ness - Play five matches OR Reflect ten projecticles OR meet Ness in SSE
Marth - Complete Classic Mode using Ike
Snake - Play 10 matches on Shadow Moses Island
Sonic - Complete the Subspace Emissary

Unlockable Modes
All-Star Mode - Unlock all the hidden characters

Selecting Zero Suit Samus
To use Zero Suit Samus at the start of a match, select Samus on the character screen and hold the following button before the match starts with the corresponding controller that is being used:

Gamecube/Classic controller - Hold the button.
Wii Remote with Nunchuk - Hold the button.
Wii Remote - Hold the button.

Unlock Stage Builder Parts
Parts A - Play 10 vs. matches on Stage Builder Stages.
Parts B - Create 5 Stages in Stage Builder.
Parts C - Create 15 Stages in Stage Builder.

Switch Between Samus and Zero Suit Samus
At any time during a match, quickly use an Up Taunt, a Down Taunt, and an Up Taunt. It's not a Final Smash, so you will not do damage.

Unlock Stages
Perform the following tasks to unlock the corresponding stages:

75m - Play as DK 20 times
Big Blue (old) - Play as Falcon 10 times
Electroplankton - Complete Event Match #28
Flat Zone 2 - Unlock Mr. Game & Watch
Frozen Hillside - Fight on the Halberd Stage 10 times
Great Sea - Unlock Toon Link
Green Greens - Play as Kirby 20 times
Green Hill Zone - Unlock Sonic
Jungle Japes - Fight in VS. Mode 10 times
Luigi's Mansion - Fight with Luigi in VS. Mode 3 times
Mario Bros. - Complete Event Match #19
Pokémon Stadium - Fight in Pokémon Stadium 2 10 times (VS. Mode)
Port Town - Play as Falcon 10 times (VS. Mode)
Spear Pillar - Complete Event Match #25

Unlock Virtual Console Trials
You can unlock Virtual Console trials of old classic Nintendo games by performing the following:

Donkey Kong - Play SSBB for ten hours.
F-Zero - Complete the Subspace Emissary.
Super Mario Bros. 2 (USA) - Win with Peach in VS. mode five times.
Super Mario World - Play on Yoshi's Island's stage three times.
The Legend of Zelda - Play as Toon Link ten times.

K.K. Slider Concert
If you play any kind of Brawl on the "Smashville" Animal Crossing stage when your Wii's internal clock is set to a Saturday between the hours of 8:00 PM and midnight, K.K. "Totakeke" Slider will appear in the background of the stage and serenade your brawl.

Unlock Hidden Assist Trophies
There are 6 secret assist trophies in total. Below are the methods for unlocking them.

Advance Wars Assist Trophy - Play 300 brawls.
Barbara Assist Trophy - Unlock 25 or more CDs.
Gray Fox Assist Trophy - Unlock Snake.
Isaac Assist Trophy - Play 200 brawls.
Ray MK III Assist Trophy - Play 100 brawls.
Shadow the Hedgehog Assist Trophy - Unlock Sonic the Hedgehog.

New Sound Test Categories
To hear the sounds from these new categories in the sound test, do the following:

Fanfare - Unlock all characters.
Assist Trophies 3 - Unlock all assist trophies.
Kirby's Copy Abilities - Unlock all characters.
Narration - Unlock Boss Battles and All-Star.
Subspace Enemies and Bosses - Clear the subspace emissary.

Random Stage Switch
To unlock random stage switch under the rules option, you need to unlock all the stages with additional rules enabled.

Fight Crazy Hand in Classic Mode
To fight Crazy Hand in Classic, you must reach the Master Hand in under nine minutes and without using any continues. Also, it must be completed on Hard mode or higher. If these conditions are met, Crazy Hand will appear alongside Master Hand at the start of the match.