-Ok here is something that is fun to do, well not really fun i guess but just knowing that you have done something that you aren't supposed to.  Ok first open up Microsoft Paint, then go to open then type (or copy and paste) C:\Windows\logo.sys.  Then you can change how the "It Is Now Safe To Turn Off Your Computer" sign.  Any way you choose and it doesn't affect your computer one bit!

AoE Codes!
Big Bertha:Gives cats a range of 16 and a damage diameter of 10.
BigDaddy: Gives you a car with a rocket launcher.
Coinage: Gives you 1000 gold.
Dark Rain: Makes your archers stealth.
DieDieDie: All players die.
E=MC2 Trooper: Gives you nuke trooper with a rocket launcher.
Flying Dutchman: Allows Juggernauts to travel over land.
Gaia : Gives you control over the gaia units.
HariKari: Kill yourself.
Home Run: Wins the Level.
HOYOHOYO: Gives priests the speed of a horse and hit points of an elephant.
ICBM: Gives your ballistas a range of 100.
Jack Be Nimble: Makes you catapults shoot villagers and cows.
Medusa: Makes all villagers into medusa's.
No Fog: Removes Fog of war.
Pepperoni Pizza: Gives you 1000 food.
Photon Man: Gives you the Nuke Trooper with a laser weapon.
Quarry: Gives you 1000 Stone.
Resign: Resign.
Reveal Map: Reveals the entire map.
Steroids: Makes your villagers train faster.
Woodstock: Gives you 1000 wood.
steroids: builds instantly

Starcraft Codes!
PowerOverwhelming Units become invincible.
Show me the Money Gain 10,000 gas and 10,000 crystal.
Black Sheep Wall Entire Map Revealed.
Operation CWAL Speed up the construction of buildings and units.
Something for Nothing Everything available is upgraded.
War ain't what it used to be No fog of war.
Modify the Phase Variance Gain ability to build any building, regardless of requirements.
The Gathering Gain unlimited energy to all casting units.
there is no cow level Completes current mission.
Food for thought Ability to build units beyond the support limit.
medieval man Gives free upgrades to units.
noglues Computer can't use energy.
ophelia Enter this to enable level skipping cheat. Then enter the mission you want to skip to (e.g. "terran10").
Breathe Deep Gives you 500 Vespene Gas.
Whats mine is mine Gives you 500 minerals.
Staying Alive Prevents the mission from ending due to Victory or Defeat.
Game over man Instant Loss.