The original 3D GTA. Liberty City, Claude, and the birth of an open-world genre.
GTA III's PC version uses typed cheat words; PS2 and Xbox use button combos entered on the controller during gameplay. Codes shown are the original PS2/PC/Xbox set; the Definitive Edition re-releases preserve the original combos.
Cheats may disable trophies / achievements for the current play session on most modern entries — save in a free slot before experimenting.