Okay. I think it would be the Doctor :D Well, seriously, it would be the Tardis, because sometimes I just want to run away... But actually I don't think... I mean it's the Doctor, so I don't want to steal anything from him. I want to be his friend not his enemy. But I really want to have the Tardis :)
I am like Bowser in that I will steal the Princess and the Doctor must go through several trials to retrieve him, as well as step on a few mushrooms. Because mushrooms are gross.