Skullwaker on 01 May 2015
My guess is Splatoon. I feel as though it has a more broad market (it appeals to fans of platformers and shooters alike) while XCX has a more narrow appeal (the JRPG market is pretty niche in comparison).
It will be close though, I think. I predict both will be 1 million sellers, and I have a feeling at least one will get to 2m.
