I was figuring NKG. GPZ just has a thing where you can repeat the fight, it intensifies a bit, and while GPZ 1 is very manageable GPZ 10 is some nonsense.

Anyways, back to the main thrust of the thread - there's also some games that aren't out yet that could tip this. Metroid Prime 4 is supposed to be out at some point, and it's back in the hands of Retro Studios.