Super Mario Odyssey

Fallout 4 for me. I'm pretty sure it's blazed past Skyrim for most hours I've put into a game. It's all the possibilities, all the ways you can shape your game, that make it the best roleplaying game I've ever booted up. I'll play other games and while I'm doing that, they'll give me ideas for things I want to do in Fallout 4, which prompts me to jump back in and start a new game with a new theme or purpose. For example, I've played in a world where the Minutemen were going down a dark path of oppression and violence. In another, I created a lot of raider controlled settlements. In another, I expanded the Institute's presence above ground.

Portal 2 is up there, as well. It succeeded on SO MANY levels. Storytelling done right.

My top three would be:
1. Breath of the Wild
2. Hollow Knight
3. Donkey Kong Country: Tropical Freeze

Honorable Mentions: Super Mario Odyssey, Celeste, Super Smash Bros Ultimate, Elder Scrolls: Skyrim, and Super Mario Galaxy 2.

Skyrim VR
Never before have I been so immersed in a Game. VR itself is what defined the last 10 years of gaming for me. Skyrim VR is the game I spent the most time with.

Close second: The Binding of Isaac
You can play this game over and over and over and over. It never gets boring.

1st place goes to Legend of Zelda Breath of the Wild.

Witcher 3 is a close second.

Persona 5 takes 3rd.

The Last of Us. It pushed storytelling, and graphic detail beyond what was thought possible at release. I hadn't been as hooked on a game's story since FFVII. Truly a masterpiece.
Runner ups:
Skyrim,
Breath of the Wild,
Super Mario Odyssey.

Breath of the Wild, speaks for itself tbh people are still finding and creating new tricks and ways to play now almost 3 years after launch the gameplay is so customizable and the scenarios that can happen in the game are so out there no game can recreate what goes on in it.

The Legend of Zelda: Breath of the Wild.

Uncharted 4 where i played about 450 hours on multiplayer, without mention the quality of the game.

Persona 5 or Nier Automata. Tough choice.
Other honorable mentions: Sekiro, Astral Chain, Persona 4 Golden, FF Type-0 HD, FF XV, MGS V, Doom (2016). These were the most enjoyable and memorable games of the decade I guess.
Celeste is my personal indie game of the decade.