Old school rules!
Laugh if you must, but the only cheat code I remember is Down-Back-B for Shaq-Fu on Sega Genesis.
Depending on what character you had, it would make you do a pretty cool special move.
Also there were some pretty spiffy codes for Daytona USA for Sega Saturn. (yes, I own that system.. one of the few who actually bought it.)
One of them let you drive as a horse instead of a car, and another one made your car's wheels disappear, yet somehow keep rolling.
Good times had back in the day..
Oh, speaking of racing games, in the original driver there was a cheat code to get your car on "stilts" and your suspension was like.. 5' tall. It was awesome for cruising straight.. but one wrong hard turn and you were flipped.
That game was invaluable for it's lesson to kids back then to not buy and/or race SUV's or you would go flippy flippy..
