Ah, this brings back so many memories. ♥
Back in 2000, my freshman year in college, I had a Game Genie *and* the code that would spawn Mews into the game, and I made a pretty penny by selling them to my classmates (and even a couple professors!) for €10 a pop. ;)
Also, anyone remembers that goshdarned cheat that supposedly allowed you to play as the bosses in the original SNES Street Fighter II game, that then turned out to be fake? I spent so many hours in front of my SNES compulsively trying to make it work... ;_;