Just For those too lazy to look for these.

Full health and armor



Full health, armor, and ammunition



Weapons tier 1



Weapons tier 2



Remove Niko's wanted level



Spawn Annihilator police helicopter



Spawn Cognoscenti



Spawn Comet



Spawn FBI Buffalo



Spawn Jetmax



Spawn NRG-900



Spawn Sanchez



Spawn SuperGT



Spawn Turismo



Change weather and brightness



The following codes require "The Lost And Damned" bonus downloadable content

Spawn Burrito



Spawn Double T bike



Spawn Hakuchou bike



Spawn Hexer bike



Spawn Innovation bike



Spawn Slamvan





The following codes require "The Ballad Of Gay Tony" bonus downloadable content

Explosive sniper rifle shots



Super punch



Spawn Akuma bike



Spawn APC



Spawn Bullet GT



Spawn Buzzard helicopter



Spawn Floater boat



Spawn parachute



Spawn Vader bike