nintendo 64 codes:
goldeneye 007: paintbrush weapon- begin a multi-player mode game in a level that contains sniper rifles. Collect a sniper rifle before getting any ammo or touching another character. Press A(2) after getting the sniper rifle to use a paintbrush.

legend of zelda-ocarina of time:unlimited money-go to the Lost Woods and find the Skull Kid who is alone as adult Link. Then, lock onto and kill him, and he will give you 200 rupees. Enter a door, return, and repeat the process to collect an unlimited amount of money.
 

turok 2:seeds of evil:cheat codes-enter one of the following codes at the "Enter Cheat" screen. Then, start a game and pause. Now enter the cheat menu and set each enabled code as desired. All cheats entered can be saved after reaching a save point.

pc codes:
grand theft auto-enter all these codes in place of the characters names
                         :all levels-nineinarow
                         :unlimited lives-itstantrum
                         :no police-iamthelaw
                         :999999999 points-itcould be you

command & coquer-redalert-faster units:build a mine layer and put in a group with something slow like a mammoth tanks. Then make them a group and then a formation. Now all units will travel the speed of a mine layer.