I'm not really like any of the characters up there.  If I had to choose I'd say Luigi, just because he's kind of shy and pretty clumsy, but he still doesn't seem to do it for me.
Hmmm....  I think that there's yet to be a Mario character that I can truly relate to.  Until then, I'm going to stick with Bobbery...only in a younger form...and without the huge grey mustache....and not as a salty seaman...  ^_^'  This is simply because he seems like a polite person who is unafraid of showing good leadership when need be, and is capable of giving wise advise.  And on top of that, he's super modest.