Decided to go ahead and make a spreadsheet of all the first party Nintendo games that have exceeded 10 million units (as of the most recent sales update).

https://1drv.ms/x/s!Agxa_hJAdjd7geB7aza0NhUWqDXOzg?e=lX1KkV&nav=MTVfezAwMDAwMDAwLTAwMDEtMDAwMC0wMDAwLTAwMDAwMDAwMDAwMH0

There are 52 first party Nintendo games that have exceeded 10 million units (and I expect that number to continue to rise with Switch over the next few years. The Switch has the most 10 million sellers, but Wii's 10 million sellers have actually sold the most (thanks to Wii Sports being bundled), but I do expect Switch to overtake possibly as early as the end of next year.

As expected, neither GameCube nor Wii U had any 10 million sellers on the list, which also means that none of their games are in the Top 50. Also, 10 games on the list have exceeded 30 million sales and almost half of the 10 million sellers have exceeded 20 million. Of the games on the list, N64 has the smallest presence with just 1 game (MK64 narrowly missed the list).

The total sales of all the games on the list exceeds 1 billion! How many 10 million sellers do you think will there be in total at the end of Switch's life? (Feel free to include games that haven't been announced yet in your guess, such as Gen 9 Pokemon.)

Im assuming this excludes remasters and remakes? Curious if OoT and TP would be over 10 million if we include those.

Upcoming 10m sellers:
Diamond & Pearl Remakes
Pokemon Legends Arceus
Splatoon 3
BOTW 2
Mario Party Superstars

So should get to at least 57 just with games already announced. Not sure what comes after that before the Switch's end, but I'm going to say 60.

They are included, but sales are separate from the original games. These are the numbers I found:

Ocarina of Time (N64) - 7.6m
Ocarina of Time (3DS) - 6.2m

Twilight Princess (Wii+GCN)  - 8.85m
Twilight Princess (WiiU) - 1.13m

Combined with the original both would be over 10m. (Well Twilight 9.98m, but I imagine it could have sold an extra 0.02m after whenever that WiiU figure was collected)

Breath of the Wild 2
Brilliant Diamond/Shining Pearl
Mario Party Superstars
Legends Arceus
Splatoon 3

That's at least 5.

Mario Maker 2 and Bowser's Fury will get there eventually, so 7.

And I'm almost certain we're going to get at least 1 more 3D Mario game and/or Pokemon Gen 9 at some point. So when those drop, that'll be 8-9.

So it'll be either 60 or 61. Because I could easily see them saving the next 3D Mario for Switch 2 so that Switch 2 has that game + Mario Kart 9 in the first year, with one of them being a launch title.

@brute @Zippy6 Correct, remakes like OoT 3D & TP HD are considered separate from their originals.

As far as the end of Switch's life, I voted for 61, with the additions being as followed:

Mario Maker 2
Bowser's Fury
Mario Party Superstars
BDSP
Legends
Splatoon 3
BOTW 2
Pokemon Gen 9
Pokemon Let's Go, Johto

This would give the Switch 21 games exceeding 10 million sales (out of 61 games). I imagine it would be a similar situation with Switch 2.

I'll go with 63, I think we still get a few huge unannounced games before the next console comes out. Some pretty impressive attach rates on some of those games like Mario 64, Mario Kart Wii, Mario Kart 8 Deluxe, Animal Crossing and some others considering they weren't packed in games. (Mario Kart 8 was packed in a bit during Black Friday

Games already released that will cross 10m:

Super Mario Maker (probably)
Mario 3D World + Bowser's Fury
Mario Party Superstars

That brings the total to 55.  Games soon to be released:

BDSP
Arceus
BotW2
Splatoon 3
Next mainline Pokemon

That brings the total to 60.  Then the big mystery is how many unannounced games are left that will cross the 10m mark.  I am going to guess 3.  There are a whole lot of possibilities, but Nintendo will only choose some of them (Tomodachi, popular port(s), another Mario Party, Mario Kart 9, 2D Mario, Wii Sports 3, RFA2, etc...).

So, I'm going to guess 63.

Pokemon BDSP
Pokemon Legends Arceus
Botw 2
3D World (dont remember if it got there already)
MPSuperstars
Next mainline Mario game
Another pokemon game
Splatoon 3

And maybe 2 other surprise titles that will get there. So i think there should be around 10 new 10 million sellers in the Switch era

edit : also kinda crazy to realize Botw, a Zelda game, will enter the top 10 best selling Nintendo games of all time. That’s crazy to think about. It will eventually dethrone SMBWii and DS… which were monster hits.

@xMetroid It might even surpass Super Mario Bros. I could see BOTW's final sales exceeding 40 million. (Though by that point, MK8 DX & ACNH will be way above it and SSBU might still be above it).