Even though the NS2 is shaping up to have an impressive 2025 lineup (and it's possible that they might not have revealed everything just yet), I would still give it to NS1 2017 so far. Hard to top 3D Mario, Zelda and Mario Kart. If we actually end up getting 3D Mario this year, I might put NS2 above NS1, depending on how that goes since NS1 got a Mario Kart port instead of a brand new one.

I know the poll is first party only, but the big advantage Switch 2 has is third party.

There were very few such games in Switch 1's first year, while Switch 2 is packed with them; Cyberpunk, Split Fiction, Street Fighter, Hitman, Daemon x Machina 2, Elden Ring, Final Fantasy 7, Borderlands 4, etc.

A tricky thing is the Switch sharing three of its launch year games with the previous Nintendo system didn't matter cause it was a huge flop but the Switch 2 sharing Prime 4 and Legends Z-A with the Switch is significant due to how massive of a success the platform is so for some people those won't be "true" Switch 2 games and a reason to buy one. Overall the Switch had a stronger start for the average person first party wise due to that I'd say but the Switch 2 is looking like it'll have a really strong start too considering the three less months.

I feel like the kind of players who are interested in Prime 4 are the sort of enthusiast players who would also buy a Switch 2 in its first year, so I wouldn't be surprised if the game is a bigger deal on Switch 2 than Switch 1.

As for Pokémon, while it's audience is more casual, I think the draw of finally having halfway decent performance in a modern Pokémon title might draw many to get the Switch 2 version.

Oh yeah I do expect Prime 4 to sell more on the Switch 2 and for a huge chunk of Legends Z-A sales to be that version, them releasing so early in the Switch 2's life just makes them feel more like enhanced Switch 1 games than Switch 2 games downported to the Switch 1 so will reduce their Switch 2 selling power quite a bit.

It is notable that the Switch 2 will benefit from mainline Pokemon sooner than any previous Nintendo system though. Gold and Silver were 1-2 years after the launch of the GBC depending on region and BW2 could be played on the 3DS but there wasn't really a benefit from doing that.

I still think both will have considerable selling power on Switch 2 in spite of being crossgen; not as much as if they were exclusive, but still, the kind of gamers who are interested in Prime 4 will want to play it in the best quality, while Pokémon without awful performance has been a dream for series fans for years now.

Crossgen games have been major sellers before, with titles like God of War Ragnarok and Horizon Forbidden West on PS5, or Titanfall, Destiny, Battlefield 4, MGS5 etc during the 7th/8th gen shift.

I agree that Legends Z-A will still have significant selling for the Switch 2 though not so much for Prime 4 though that's mostly due the Metroid series being on the niche side. There's also that the marketing for it has not exactly been great so far so hopefully that improves soon since the series needs as many newcomers buying this game as possible considering how long it's taken to make.

In an ironic twist of fate, or perhaps fitting, I didn't have a PlayStation or Xbox for many years. I wanted more third-party from Switch, especially in the first year. 

But I've had a PlayStation since 2019. When Nintendo is launching a console that's going all in on third-party is when I don't need those games. There are very few third-party exclusives announced for Switch 2 right now. I'd rather play multiplats on PS5 because of better specs and trophies. 

Switch 2 easily. Mario Kart, 3D DK, Metroid w/ mouse controls, 3D Pokemon, Drive & Drag, and Gamecube being added.

Mario Kart World > Mario Kart 8 Deluxe

DK Banaza < Zelda BoTW

Welcome Tour < 1, 2 Switch

Drive & Drag > Arms

Metroid Prime 4 > Splatoon 2

Kirby Airriders > Mario Rabids

Pokemon Legends ZA > Mario Odyssey 

Hyrule Warriors AoI < Xenoblade 2

Switch 2 enhanced games and GC added > Pokken DX & Fire Emblem Warriors

6 to 3 in favor of Switch 2

I think it boils down to which platforms you own. If you have a Switch you can play MP4, Pokemon, the Zeldas, it's just a better version available on the Switch 2. At the same time if you had a Wii U back in the day you could already play BOTW, MK8, and a lot of the other games that were ported later on...

Same with the third parties, all have been available for years on other platforms and better versions to boot.

Overall though I think the Switch wins out because almost nobody played Wii U games in the first place and it's extremely hard to beat MK8+BOTW+Odyssey in the same year. Even if we have a new 3D Mario for the holiday I think the Switch 1 would eke out a win here.