I think The Witcher 3 would clean up, but it would still be fun to run. The games that stood out to me personally:
2010: God of War III
2011: Portal 2, Skyrim, Uncharted 3, The Legend of Zelda: Skyward Sword, LA Noire
2012: Journey, Far Cry 3
2013: The Last of Us, BioShock: Infinite
2014: Don't think there's anything worth mentioning, Far Cry 4 and The Evil Within were probably my favorite games of the year.
2015: The Witcher 3, Undertale, Fallout 4, Bloodborne
2016: Uncharted 4, Firewatch
2017: Another year where nothing stood out, although I think this is more my fault for not checking enough games out rather than there being a lack of good games.
2018: God of War
2019: Don't think I've even played anything released this year yet, as you can see from my list I've been slacking with video games the last few years.
If I were to rank them:
1. The Witcher 3
2. Portal 2
3. The Last of Us
4. Uncharted 3
5. Skyrim
6. BioShock: Infinite
7. Uncharted 4
8. Far Cry 3
9. Undertale
10. Journey - this is a weird one, I have it as my game of the year over Far Cry 3 in 2012, but if we're looking at it in the context of a decade I feel like replayability should be a bit more of a factor for some reason. This game straight up as zero replayability.