The following codes are for the Playstation.. if you have the pc version download the crack
HERE
Enter any of the following codes as a player name. You may enter multiple names.

NAVARONE	All weapons
ITSALLUP	Level select
MUCHCASH	Extra money
LIVELONG	Unlimited energy
BIGSCORE	10 million points
LOSEFEDS	No police
DESIRES	Maximum wanted level
NOFRILLS	Debug basic scripts
HIGHFIVE	5x multiplier
WUGGLES	Display coordinates

Gameshark Codes (38 codes total)

Pistol Max Ammo	D0164D6C 0000 80164D6C 03E7
S-Uzi Machine Gun Max Ammo	D0164D94 0000 80164D94 03E7
Shotgun Max Ammo	D0164E5C 0000 80164E5C 03E7
Rocket Launcher Max Ammo	D0164DBC 0000 80164DBC 03E7
Flame Thrower Max Ammo	D0164EAC 0000 80164EAC 03E7
Electro Gun Max Ammo	D0164E84 0000 80164E84 03E7
Grenades Max Ammo	D0164E34 0000 80164E34 03E7
Molotov Cocktail Max Ammo	D0164E0C 0000 80164E0C 03E7
Zapper Max Ammo	D0164DE4 0000 80164DE4 03E7
No Kills	8012A870 0000
No Cops	80145A8E 0000
Infinite Bonus & Kill Frenzy Time	800A419A 2400
Lots of Cops	80145A8E 2EE0
Max Number of Kills	8012A870 FFFF
Max Money	8011FD0C 967F 8011FD0E 0098
Infinite Lives	80120008 0063
Infinite Health	80145A9A 0064
Joker Command	D0035510 ????
All Weapons	D0164D6C 0000 50000B28 0000 80164D6C 03E7
Open All Normal Areas	80024F24 0003
Open All Bonus Areas	D0024F1C 0000 80024F1C 0001 80024F28 0009
Invincible	30026348 0001
All Areas Unlocked	30026349 0001
No Cops	3002634A 0001
5x Multiplier	3002634B 0001
10 Million Points	3002634C 0001
All Weapons	3002634E 0001
Most Wanted	3002634F 0001
Blood Mode	30026351 0001
Respect From All Gangs	801789E4 7530 801788B4 7530 80178784 7530
Display X Y Coordinates	30026350 0001
Bonus Multiplier x99	80120040 0063

Fly	Select Molotov cocktails jump off roof keep pushing fire
Elvis	Get a car and run over a group of Elvis's all in a straight line so they all die at the same time to get the bonus