It depends on what kind of Mario title it is. If it's like Mario 64... some huge, revolutionary full on 3D game that blows minds? It would be the bigger game. If not, then I say Splatoon because it's a shooter and people are eating it up right now.

I think NX will be released in 2016.

Which would be the year of NX launch :)

A full 3D Mario, Splatoon 2 coupled with Zelda U and Mario Kart 8 -NX would set up for a solid launch.

One thing is having a strong launch, and other is playing your best cards at the beginning. XD

With all the software drought problems Nintendo has had this gen, I'd rather choose a slow but consistent lineup than everything from the get go.

They could..... Re-release Smash (let's face it, the roster is unbeatable).

Yup, that's why I went with 2 standard games and 2 Wii U ports initially. Then Smash Bros a few months in. Basically make the Wii U games GOTY edition type things. 1080p native resolution and in Mario Karts case 60fps 3 and 4 player split screen and a few extra tracks and I would pay £40 all over again.

So the answer to Nintendo's Wii U woes is to rerelease every Wii U game? That would demolish the diehard fanbase, I would leave, seriously. Then during their next identity crisis they would have noone,and earned it.

Since I think NX will release this year I'm gona say Mario since I think they'll build more hype around Spla2n

odd odd odd question

Splatoon is nowhere near a Mario title at this point. its not even a debate.  

the best NX opening title they could have would be a Mario Galaxy game, there has been a lot of open bitterness that there was no Mario Galaxy for the Wii U from fans