Any 3rd installment of a game that fans have been waiting for. Games that have got petitions to get companies to make and has fans begging for. games like sonic adventure 3, megaman legends 3, kingdom hearts 3, and everything valve has made. I think people would get really REALLY angry if nintendo decided to buy platinum games but it would be a good move and the nintendo fans would love for that to happen

Though this is hardly realistic, yes, hearing the million fans suddenly cry out in terror would be comedy gold.

Call of Duty: Modern Warfare Trilogy - Screw U Edition

World of Warcraft 2 - A Wii U exclusive.

@LinkVPit. Definitely.

One Word..................

Worms 3D

From a Japanese perspective, Persona 5, it's bigger than the mainline SMT series and has been a Sony exclusive series. (Arena doesn't count)
It's vaguely possible what with Atlus working with Nintendo for their Fire Emblem crossover game, although the Persona team is separate from SMT because it's gotten so big now.

Hahahaha at this stage Nobody will be getting that game :P

Call of Duty.  (Still don't see the mass appeal in that game, but whatever floats thier boats)

MindCraft. 

Doom.

I'm gonna say, Half Life 3.

It's been years without a word from Valve about Half life, turns out they just got bought by Nintendo and were doing the paperwork :P