Yeah I'm gonna go with 2017 as well. In addition to the amazing combo of BOTW + Mario Odyssey, Splatoon 2, Xenoblade 2, Mario + Rabbids, and Doom were also excellent.

2019 is no slouch though with Hellblade, Witcher 3, Yooka Laylee & The Impossible Lair, Luigi's Mansion 3, Yoshi's Crafted World, and Trine 4.

Both beat any year of the Wii U and any year of the Wii outside of 2010.

2017 was definitely the more exciting year, and the year with the stronger releases. 2019 is the more satisfying year because there's the new stuff, but ALSO all those amazing games from 2017. Most of the games I got in 2017 are still among my main games played in 2020 - and not because of a lack of compelling content from last year - just that the 2017 games were that damn good. I've probably played Mario Kart 8 for 150-250 days in 2019, and I still play Stardew Valley regularly (how that holds up after March and Animal Crossing remains to be seen. Also the Rune Factory games), and I played a lot of Zelda over the last month and a bit (mostly because I've been playing The Witcher 3, which IMO is significantly better than Skyrim).

The games I bought
2017: Zelda BOTW, Arms, Mario Kingdom Battle, Splatoon 2
2019: FE 3H , Luigi Mansion 3 (Just for my brother)

So 2019 easily wins. Imo no other year will beat it.

I'm going 2019.... there were so many awesome games, all the time. I never stopped playing my switch this year.. at all. Fire emblem: three houses.... that was the icing on the most amazing cake ever. What a year... and I know what 2017 brought. So, that's saying ALOT about 2019.

I bought more games in 2019 than any other year of gaming in my life save the aforementioned 2010, but the average level of quality was just that bit higher in 2017 for me.

Well Breath of the Wild is the greatest game this gen so far...so the year that one came out.

It's so rare to have any system release 2 games on the level of BOTW and Mario Odyssey in the same year, I'd say 2019 had the superior quantity of good games, but as great as Fire Emblem 3 Houses and Astral Chain are, the best of 2017 is just on a whole other level.

2018, it had Kirby.

Indeed.

2020 will start strong with Ayesha, Escha & Logy and Shallie.

If 2020 is even competitive with 2017 and 2019 for me, I'll be thrilled. I can't recall any system ever having three years I rate that highly.