I'm from a younger subset than most people here and so I'll have to say Pokemon.
Before anyone screams pedophila or beastiality, the version in my head would be a lot different.. The characters are all grown up, instead of keeping little monsters as pets they keep humans, in cosplay and bondage, as pets. The battles are an issue of 'lasting', basically whoever cums first loses.
The pikachu cosplayer would have a secret move with electrostim toys and the bulbasaur cosplayer would use whips. Charmanders cosplayer, candles and hot wax, and squirtle would always be, er... premature.
Of course if there was ever a battle that couldn't be settled by their cute little 'pets' then the trainers themselves would have to get involved. The stadium concept would be the ultimate in voyeur and so some 'pokemon' would be too shy to battle. Oh, and the move earthquake, which is vastly overpowered in the game series.. would have to be done with the Hitachi.
It'd be amazingly weird, at least. I'd watch it.