2019, but only by a hair. The two Dragon Quest games (Builder 1 and XI S) along with Fire Emblem 3 Houses and Super Mario Maker 2 that are decisive for the victory of 2019 for me, but the overall quantity of great games in 2019 should also do the trick for many; 2017 had some truly exceptional games, but not enough of them to counter the slew of great titles from 2019.
The Nintendo eShop rating Thread: http://gamrconnect.vgchartz.com/thread.php?id=237454 List as Google Doc: https://docs.google.com/spreadsheets/d/1aW2hXQT1TheElVS7z-F3pP-7nbqdrDqWNTxl6JoJWBY/edit?usp=sharing
The Steam/GOG key gifting thread: https://gamrconnect.vgchartz.com/thread/242024/the-steamgog-key-gifting-thread/1/
Free Pc Games thread: https://gamrconnect.vgchartz.com/thread/248138/free-pc-games/1/