The G-Man is actually a pervert who stares at unsuspecting people. If spotted, he blushes and runs away shamefacedly.
Also, the Hunter's third leg is actually it's... penis. ( http://images.wikia.com/half-life/en/images/d/df/HuntingAlyx.jpg ). A Hunter once had sex with an A1 Abrams which gave birth to the Metal Gear Gekko.
The Turrets in Portal are remotely manned by 5-year-olds in India: to cut costs, Aperture Labs was outsourcing.
GLaDOS doesn't exist. It was Chell talking to herself all the time, patting herself on the back for solving all those awesome puzzles.
Zoey is actually sixteen. All your boners are going to jail.
Liberty Prime in Fallout had this stamped under its left leg: Made in China.
Master Chief in reality are two kids standing on top of each other pretending to be an adult to join the space marines. When Master Chief receives a head-shot, his confused pair of pants is seen running around in a disoriented fashion till someone makes a crotch-shot.
Kaiden Alenko haunts Shepard's dream, accusing him of 'picking with his boner'.
Blinky, Pinky, Inky and Clyde are actually upholders of law and order, protecting the pac-dot citizens against the menace of the monstrous Pac-Man.