1996's Super Mario 64 was the first game that bestowed Mario and his friends with a voice (well, one of the first: I don't think many of us count PC "edutainment" games like Mario Teaches Typing). While Mario's "Here we goooo!" and "Woo-hoo!" voice clips quickly became legendary, we spent decades wondering what Mario is yelling when he throws Bowser into one of the bombs lining his lair.
We finally have a concrete answer from Charles Martinet himself, the voice of Mario in Super Mario 64 (and every iteration of Mario since, to say nothing of close accomplices like Luigi, Wario, and Waluigi). According to Martinet's Twitter, When Mario seizes Bowser by his tail, winds him up, and hurls him into one of the explosive devices inexplicably placed around the perimeter of the battlefield, the hero plumber jeers "So long, Kinga Bowser!"
So long kinga Bowser!— Charles Martinet (@CharlesMartinet) April 29, 2019
This confirmation ends 23 years of uncertainty. While we sussed out the rest of Mario's Super Mario 64 dialogue decades ago, "So long, Kinga Bowser!" proved difficult to verify thanks to the echo effects present in Bowser's chamber and the loud, energetic battle music that drowns out most sound. Until now, people assumed Mario is saying "So long there, Bowser" (which is what I believed for years), or "So long big mountain," or the particularly popular "So long, gay Bowser."
Despite this ever-so-brief spell of confusion, it's hard to imagine a world where Charles Martinet isn't the jovial voice of Mario. And I'm saying this as someone who grew up with "Brooklyn Accent" Mario.