What I want to believe: Wii U. At this rate, it might actually win Japan this gen. I see some niche Japanese developers trying to make the switch from PS3 to Wii U because of similar architectures (and a higher potential for fanservice, but I digress.) A higher baseline for Wii U does wonders as well, and while system sellers don't seem to have a large impact on the baseline, their effects last longer..
What my brain tells me to believe: XBOne. Even if it competes directly with PS4, it's chasing after the mainstream market.

I WON A BET AGAINST AZUREN! WOOOOOOOOOOAAAAAAAAHHHHHHHHHHHHHHHHHHH
:3







