I’m thinking 2015 - Witcher 3, Undertale, and Kerbal Space Program are all classics. Fallout 4, Arkham Knight, and Cities Skylines were all excellent too, though fallout 4 and Arkham knight aren’t necessarily the best games in their respective series.
Ditto this, 2007 was a fucking crazy year. All that next gen hit at once, people still taking risks on unique ideas. Nowadays you only see that kind of stuff from the indie scene, though they’ve been doing a great job with it IMO.