First I love slow paced games. Second I love games with progression, so I can build up characters, items or what else. That surely points in the direction of RPG's, but i am kind of overfed with them. Both MMO RPG and Single Player. The reason is lack of innovation, most games all now look or act like games I played before - so I got bored of most RPG's; and note that great graphics and story don't do it for me either as I skip story (yeah I know ...) and good graphics are normal for games now.
Second I am in the industry since 30 years meaning I have played thousands of games. So even little things in UI or game play disturb me and I quit - and play the next.
Third I can extrapolate how most games unfold game mechanic wise if I played it for 30 minutes. This makes it challenging to keep me interested, to surprise me or to overcome my threshold.
Fourth, I am "old" - this mean reflexes are less and too twitchy games don't do it for me - unless the game designer put in classes which can be played by older players. Just like World of Tanks did - or recently Overwatch.
So which game did all this to me to get my GOTY pick?
The Division by Ubisoft.
Yes, it had a rocky start regarding update policy, but the recent patches corrected most of it. I love the game as I can pick my pace. The game doesn't force me into anything, which is exactly what I need. Sometimes I can just go for a stroll into the city and still have fun. Or go on a raid or adventure. OR find new gear. Or craft. OR join friends and do silly things.
Close contenders? The Last Guardian - as it is art. Dishonored 2 - as I can pick my pace.