In Starcraft 2: Wings of Liberty for the PC, there is a cheat become invincible, and it also has an added bonus of increasing your damage. During the game hit the Enter key to bring up the message prompt and type in terribleterribledamage to enable the cheat.
Note that once cheats are turned on, you will not get achievements for that game.
Check out my other article for more Starcraft 2: Wings of Liberty Cheats.