2. Mario and Pauline
Back when Mario first appeared, he was a carpenter, not a plumber. He was also called Jumpman, and his girlfriend was Pauline. Donkey Kong, in his eponymous arcade game, kidnapped Pauline, possibly as revenge for being mistreated. The story is hazy, and the Donkey Kong that kidnapped her may not even be the same one that’s in the modern games (Cranky Kong was, and that’s the current one’s grandfather), but whoever did it is irrelevant. Mario and Pauline were obviously so serious that he went and risked his life against a massive, unnaturally strong ape in order to save her, all the while avoiding projectiles being hurled at him. He succeeds, and they live happily ever after…until he leaves her for Princess Peach.
Pauline returns in the Mario vs. Donkey Kong series as Mario’s ‘guest of honour’ at the grand opening of the Super Mini Mario World Theme Park (the name Super Mario Land was already taken). Now, sure, they could just be good friends, and the manual refers to them as just that, but really? To paraphrase Carrie Bradshaw, Can you ever be just ‘really good friends’ with your ex? After being saved, she calls him her hero, and then begins working at Mario’s toy factory. Their past relationship is never mentioned in-game, but we all know they’re still seeing each other. Why else would Mario keep her around, and flirt with her? Maybe he and Peach have an open relationship, which is plausible, when you consider the possiblity of her and Bowser. Plus, if Peach already knows, then it rules out the possibility of them being executed for treason.