I like how Samus vs. Ridley is beating Big Boss vs. The Boss because NintendoFAQs, even though Samus/Ridley isn't a rivalry, at all.
*Spoilers!*
The final battle will be Link vs. Mario, because NintendoFAQs, even though they have even less of a rivalry than Samus and Ridley. Not sure who will win out of those, but who gives a ****. Nintendo is only relevant to people who play Bejeweled and Angry Birds now.