These are on like every site in the world, gamefaqs, etc...
Only found a few myself but not like I had to add them to the list...

GAME CODES:
Code:
Invincibility
Enter "CORTOSIS" as a code.

Infinite Force
Enter "VERGENCE" as a code.

1,000,000 Force point
Enter "SPEEDER" as a code.

All Force powers
Enter "TYRANUS" as a code to unlock all Force powers.

Maximum Force power level
Enter "KATARN" as a code.

Maximum combo level
Enter "COUNTDOOKU" as a code.

Amplified damage
Enter "LIGHTSABER" as a code.

New combo 
Enter "MARAJADE" as a code.
ALL COSTUMES
Code:
All costumes
Enter "GRANDMOFF" as a code to unlock all costume.
SINGLE COSTUME UNLOCKS
Code:
Kento's robe
Enter "WOOKIEE" as a code to unlock Kento's robe.

Ceremonial Jedi robes
Enter "DANTOOINE" as a code to unlock the Ceremonial Jedi robes.

Sith robes 
Enter "HOLOCRON" as a code to unlock the Sith robes.

Sith Stalker armor
Enter "KORRIBAN" as a code to unlock the Sith Stalker armor.

Play as 501st Legion
Enter "LEGION" as a code to unlock 501st Legion.

Play as Aayla Secura
Enter "AAYLA" as a code to unlock Aayla Secura.

Play as Admiral Ackbar
Enter "ITSATWAP" as a code to unlock Admiral Ackbar.

Play as Anakin Skywalker
Enter "CHOSENONE" as a code to unlock Anakin Skywalker.

Play as Asajj Ventress
Enter "ACOLYTE" as a code to unlock Asajj Ventress.

Play as Chop'aa Notimo
Enter "NOTIMO" as a code to unlock Chop'aa Notimo.

Play as Classic stormtrooper
Enter "TK421" as a code to unlock Classic stormtrooper.

Play as Count Dooku
Enter "SERENNO" as a code to unlock Count Dooku.

Play as Darth Desolous
Enter "PAUAN" as a code to unlock Darth Desolous.

Play as Darth Maul
Enter "ZABRAK" as a code to unlock Darth Maul.

Play as Darth Phobos
Enter "HIDDENFEAR" as a code to unlock Darth Phobos.

Play as Darth Vader
Enter "SITHLORD" as a code to unlock Darth Vader.

Play as Drexl Roosh
Enter "DREXLROOSH" as a code to unlock Drexl Roosh.

Play as Emperor Palpatine
Enter "PALPATINE" as a code to unlock Emperor Palpatine.

Play as General Rahm Kota
Enter "MANDALORE" as a code to unlock General Rahm Kota.

Play as Heavy trooper
Enter "SHOCKTROOP" as a code to unlock Heavy trooper.

Play as Juno Eclipse
Enter "ECLIPSE" as a code to unlock Juno Eclipse.

Play as Kleef 
Enter "KLEEF" as a code to unlock Kleef.

Play as Lando Calrissian
Enter "SCOUNDREL" as a code to unlock Lando Calrissian.

Play as Luke Skywalker
Enter "T16WOMPRAT" as a code to unlock Luke Skywalker.

Play as Luke Skywalker (Yavin)
Enter "YELLOWJCKT" as a code to unlock Luke Skywalker (Yavin).

Play as Mace Windu
Enter "JEDIMASTER" as a code to unlock Mace Windu.

Play as Mara Jade
Enter "MARAJADE" as a code to unlock Mara Jade.

Play as Maris Brood
Enter "MARISBROOD" as a code to unlock Maris Brook.

Play as Navy commando
Enter "STORMTROOP" as a code to unlock Navy commando.

Play as Obi Wan Kenobi
Enter "BENKENOBI" as a code to unlock Obi Wan Kenobi.

Play as Proxy
Enter "HOLOGRAM" as a code to unlock Proxy.

Play as Qui Gon Jinn
Enter "MAVERICK" as a code to unlock Qui Gon Jinn.

Play as Shaak Ti
Enter "TOGRUTA" as a code to unlock Shaak Ti.

Play as Shadow trooper
Enter "INTHEDARK" as a code to unlock Shadow trooper.

Play as Twi'lek
Enter "SECURA" as a code to unlock Twi'lek

Play as General Rahm Kota 
Enter "MANDALORE" as a code to unlock General Rahm Kota.
OTHER:
Code:
SITH LORD MODE: Successfully complete the game to unlock the Sith Lord difficulty. 

JEDI ROBE: Successfully complete the game with the Jedi ending to unlock the Jedi robe.