Here are some very cool passwords :
HARDBODY- Invicibility
VITAMINS- 31 lives
THETHING- L2 + circle to change, L2 + cross to undo
BODYSWAP- press triangle to change character during game.
OTTOFIRE- permanent weapons
CORONARY- adds hearts
BORNFREE- access all levels
TOMMYBOY- play flipper after finishing a level 
CASHDASH- Bonus stage after finishing a level