all of these arguments are moot, because everyone knows that if any of these characters were real and used their actual decks, any rl noob who picks up a structure deck (at least the new ones that have been released recently) would be able to wipe the floor with even the best and most powerful characters from the anime and manga. However, in the spirit of this discussion, I would have to say that Yami Yugi would beat out everyone, thanks to his ability to will whatever card he wants from his deck to his hand, even cards that otherwise have never been in his deck before he needed them.