The number one job we'd like to see Mario actually doing is, unsurprisingly, being a plumber. Yeah, that's how he's styled himself for years, but we have a nagging suspicion it was all just a PR move to get him painted as some sort of everyman's hero. Have you ever actually seen Mario do any plumbing? Fix a broken pipe? Tighten a valve? Install a toilet?
No one can deny that the dude is talented, and his myriad other hobbies may account for the notable lack of Mario Plumbing games currently available. He's got so much on his plate that he just can't find the time to bust out the old monkey wrench and have a look under your sink.
Or maybe he was never a plumber at all. Consider your bluff called, mustache man. Your move.