Although I can't really imagine myself as a hero. I'd probably be the villain.
I suppose I'd want to be kind of like Kayaba from SAO, just more fleshed out. Or Tet from NGNL.
I enjoy being a dungeon master of sorts, instigating challenges, making things work undetected.
If there is any protagonist that I'd want to be, it would probably be Kaito from Magic Kaito. I think that's about as much of a protag as I'd want to be, and from the perspective of Detective Conan, he's a villain.
I've Got Friends on the Other Side