Nintendo distributed this information in a news update on Switch. The notice is officially titled “The bestselling Nintendo Switch games of 2017.” However, at least for now, we have to operate under the assumption that the data is based on eShop sales in the Americas only. There are no similar notices in other territories like Europe or Japan, and the bottom of the post mentions that the news was distributed for Nintendo Account holders in the Americas.
1. Zelda: Breath of the Wild
2. Super Mario Odyssey
3. Mario Kart 8 Deluxe
4. Splatoon 2
5. Mario + Rabbids Kingdom Battle
6. ARMS
7. 1-2 Switch
8. Minecraft: Nintendo Switch Edition
9. Stardew Valley
10. Snipperclips
11. Sonic Mania
12. Pokken Tournament DX
13. Super Bomberman R
14. The Elder Scrolls V: Skyrim
15. Ultra Street Fighter II: The New Challengers
16. The Binding of Isaac: Afterbirth+
17. Xenoblade Chronicles 2
18. Puyo Puyo Tetris
19. Shovel Knight: Treasure Trove
20. Overcooked: Special Edition
Source 1: Switch News
Last edited by Shikamo - on 21 December 2017(=^・ω・^=) Kuroneko S2 - Ore no Imouto - Steam, MyAnimeList and Twitter - PSN: Gustavo_Valim - Switch FC: 6390-8693-0129 (=^・ω・^=)