While 20 mil is higher than most Pokémon games do, judging by Sword and Shield, the Gen 9 Pokémon games are a safe bet (and they'll definitely be on Switch).
Other than that I can only see MK9 reaching that mark, but I honestly think they might save that for the next console (maybe a launch title?) since MK8DX is on track to beat the franchise record, despite being a port.

I'm rooting for pikmin 4 if it ever get's released. Luigi's mansion might if its legs hold up.

We have no idea how much demand there is for ring fit. It could be big enough for 20 million but its impossible to tell with stock issues. If switch sports ever happen I’m sure it would do 20 million as well

I think at this point they should keep MK9 as a launch title for the switch successor. If the successor launches with that it's guaranteed to have a very successful, maybe even record breaking launch.

Makes me wonder about the projects size in sxope and if theyll push it back for a switch 2 launch title.

A Breath of the Wild battle royale would actually be pretty damn awesome

Wow someone mentioned MP4 haha. I do agree that I think MP4 is gonna blow the lids off the typical sales of Metroid games (its a 1-2 million selling franchise, with Metroid Prime holding the record at something like only 2.7 million). I think there is a lot of anticipation for Metroid Prime 4 and if it is a critically acclaimed game I could totally see it launching Metroid into the mainstream so to speak, but still I think it'd do like 6-8 million. There's no way I see Metroid as a 10+ million seller, let alone worthy of mention in a 20 million seller thread.

For the guy who said the days of 2D Mario outselling 3D Mario are over, I feel the same way. I feel like maybe this is because when the NSMB series started 2D platformers were a novel concept and multiplayer Mario was a crazy new thing, but now with the indie scene pumping out lots of interesting 2D platformers people have a lot more options than just buying Mario to scratch their 2D platforming itch. But I'm not gonna count out the potential of a brand new fresh 2D Mario game blowing up to be a mega seller. The NSMBU port, selling at full price no less, is probably over 6 million now and will probably get to 8+ million lifetime. It's not hard to imagine a brand new 2D Mario that resets the series and feels fresh being at least 15 million or more sales and possibly going to 20 million.

I think BotW 2 and the next 3D Mario will probably not sell 20 million because I don't expect sequels to sell as much as originals (even if Mario isn't a direct sequel to Odyssey). 10 million for sure, probably 15 million, but I doubt 20 million.

We have 6 games out now that have or will definitely pass 20 million. Out of future games I see Mario 2D, Mario 3D, and BotW2 all as a maybe because I think each of them will probably fall just a few million short. So outside of Nintendo coming up with some brand new mega popular game, I'd say the best shot would be the next core Pokemon toward the end of the Switch's life (holiday 2022 I'd guess). But to do it they'd probably have to really up their game and not have the controversies of Sword/Shield because as stated, sequels will generally sell less than their first iteration on a system. I think they'd have to make the next core Pokemon really considered THE pinnacle Pokemon experience. Also I think it'd help if they don't do some remake in the meantime and just focus fully on the next core Pokemon for the next two years, as having four different Pokemon games on the Switch would probably lead to fewer people buying the last one.

So basically that's 6 current games and 4 maybes on future games but I think more likely those 4 will be 15+ million sellers and not 20 million.

wooosh

Yea I honestly agree, even though it'd be quite the wait. They can put that development effort towards something else in the meantime.

We never know with Nintendo tbh, they can surprise us with something huge coming from left field.

I think Ring Fit will surpass 10 millions maybe more. If Zelda Botw is on track to sell 25 millions on switch alone, 26-27 with the Wii U version, then I'm sure these sequel can crack the 20 millions if fresh and good enough.

The next pokemon game probably. There is a lot of hype for Gen 4 remake. I do think SS will hurt the franchise a little, some bought it but idk if they will buy a new one if the effort is still not present.