Here are some cheat codes for the game LEGO Star Wars II. Unfornunatly there are no codes for the extras. But here are the characters:
QYA828 - TIE Interceptor
HDY739 - TIE Fighter
NXL973 - IG 88
BEN917 - Ben Kenobi (Ghost)
NFX582 - Gonk Droid
HHY382 - The Emperor
MMM111 - Imperial Guard
TTT289 - Ewok
HLP221 - Boba Fett
GBU888 - Skiff Guard
SGE549 - Palace Guard
WTY721 - Bib Fortuna
YZF999 - Gamorrean Guard
VHY832 - Bespin Guard
UGN694 - Ugnaught
UUB319 - Lobot
NYU989 - Snow Trooper
CYG336 - Rebel Pilot
EKU849 - Rebel Trooper (Hoth)
YWM840 - Han Solo (Hood)
SMG219 - Grand Moff Tarkin
BBV889 - Imperial Officer
NNZ316 - TIE Fighter Pilot
BNC332 - Death Star Trooper
UCK868 - Beach Trooper
CVT125 - Imperial Spy
PEJ821 - Tuskan Raider
YDV451 - Sand Trooper
JAW499 - Jawa
NAH118 - Greedo
VAP664 - Imperial Shuttle Pilot
PTR345 - Storm Trooper
I hope these come in useful for you!