For me, it has to be 2017 for the Switch.
Theres the obvious 4: Breath of the Wild, MK8D, Splatoon 2, and Super Mario Odyssey.
Then after that, I had Sonic Mania, Xenoblade Chronicles 2, Fire Emblem Warriors, Mario & Rabbids: Kingdom Battle, NBA 2K18, Shantae: Half-Genie Hero, Fast RMX, and Sonic Forces.
The Switch absolutely needed to get off to a strong start with a great first year and thats exactly what it did which helps make it the best year for a Nintendo system Ive seen to date.
Pancho A. Ovies
Nintendo Switch in Japan (Famitsu): 2018 vs. 2019
PlayStation 4/Xbox One/Nintendo Switch: 2018 vs. 2019