Zelda has great legs and combined with the Wii U version it will reach 10 million. Splatoon 2 will as well I think, but it will be harder (and it depends on post-launch support).

Super Mario Odyssey is a no-brainer, I'm going with a riskier prediction of 15 million copies sold (including digital of course). I hope they release DLC for it as well. 

????

PS... can't wait to see some pessimistic Nintendo fans eating crow again. Since Switch launched this is becoming very common.  

OP... I agree. 

1- Zelda did 3.7m on march alone (combined), and it you look here (http://gamrconnect.vgchartz.com/thread.php?id=228876&page=1#) Switch version is tracking far ahead of Twilight Princess on Wii. It's actually incresing the gap each week! So I'm sure combined BotW will reach 10m+.

2- Mario Odyssey is a no-brainer. If the lame 3D World did 5m+ on a 14m install base, there is zero reason to think Odyssey won't reach 10m on a install base that will be 4, 5 or 6 times bigger. Many 3D Marios did it as well (Mario 64, 3D Land, Galaxy).

3- I would say Splatoon 2 is not 100% guaranteed as it depends on some things, but granted Splatoon 3 doesn't release in the next 3 years, it becomes very, very reasonable to asume it. I won't go deeper because many users already stated the reasons why, but I will spice up the things by saying that Splatoon 2 will sell 2.5m+ WW first month and between 4~5m this year alone. I guess we'll find out very soon about this one.

Splatoon 2 will sell 3 million this year, mark my words.

Definitely. I'd say it will sell 3m this quarter (July~September) alone.

Splatoon is the hardest one because we only had one game in the series and that game was at the lowest install base from a Nintendo console ever. If the original one sold 5 million on a 14 million user base, we could expect at least 10 million on Switch, but Splatoon is always hard to predict.

Careful Splatoon doubters, remember what happened last time, when the original was going to "sell on par with Wonderful 101". It's one of the most underestimated IPs of recent years.

As for Zelda, it hit 3.8 million (shipped + digital) in its first month, that should be over 6 million by the end of the year, easily. After that, selling another 4 million over the next five plus years should be a breeze.

I guess we'll see! But I don't think that all 3 of them will be able to do it myself.

Most likely, apart from Splatoon. BOTW and Odyssey will be the games to buy for the Switch for years to come (as well as MK8D). I'm not so sure about Splatoon as this is quite niche (at least so far) franchise.

Splatoon 1 sold almost as much as Smash Bros Wii U, and more than 85% of Mario 3D World. Are those niche games?