In Grand Theft Auto: San Andreas for the PS2, PC, Xbox, and Xbox 360, there are several outfits you can unlock for your character by completing various things in the game.
Croupier Outfit – Complete the “Breaking the Bank at Caliqula’s” mission
Medic Outfit – Reach 100% relationship with Katie Zhan
Overalls Outfit – Reach 100% relationship with Helena
Pimp Outfit – Reach 100% relationship with Denise Robinson
Police Outfit – Reach 100% relationship with Barbara
Racing Outfit – Reach 100% relationship with Michelle
Valet Outfit – Complete the “555 We Tip” mission