I have to say Mario as well. I mean, he's been saving Peach for decades now and there's only so many ways you can go about doing it before it all just seems like the same thing. And it happens ALL the time. I think that once Peach starts to have some relationship insecurities, Mario slides Bowser some cash to "kidnap" the princess so Mario can put on a heroic charade to remind Peach just how awesome he is.
I would say Link but I honestly have yet to touch a Zelda game so I have no room to talk. It seems like it's just more of Mario's game but after seeing Dalliah's comment I'm more open to the idea that there is more to it.