For the first half of the decade I was still gaming on a 2009 machine and as such didn't even start playing games from this decade much beyond 2010 releases until around 2017, at which point I did start catching up on the decade, but not with any real gusto.
You cannot underestimate what Dragon Age 2 did to my enthusiasm for gaming, particularly with regard to big-game releases and the notion of AAA games. It was like the end of an era for me. It doesn't matter how good the graphics are nor how good the story is, I just have no interest in that whole action/console format of gaming. Even in the 2000s I couldn't bare even the precursors to this format such as KOTOR or Morrowind, that whole design spectrum does literally zero for me.
As such I tend to find myself only really playing games from the AA and indy sector, not so much by personal choice but by the sheer lack of choice in the big-budget arena that is now entirely monopolised by one specific style of game forever reskinned and mildly altered.
Some standouts in this regard would be stuff like the Civilisation series, Total War series or the Tropico series or something like Cities Skylines. However, I haven't played any of those yet either from this decade. I never liked Civilisation 4 and stopped following that series in the 2000s, I never liked Total War 3 or 4, so stopped following that series in the 2000s as well. I can't get into Tropico at all for some reason.
I've been getting into Anno recently, but I'm only up to their 2009 release atm, Age of Wonders also, not tried the new ones yet.
So my picks for GotD would all be RPGs, and not the usual picks either, the same ones I wrote in another thread that postulated a GotD idea:
1. Blackguards
2. Lords of Xulima
3. Drkensang: The River of Time
But I also haven't tried Pathfinder yet and I am looking forward to trying that now that it's kinda done and dusted and I'll be able to buy the complete and mostly patched version this year. If I'd have played it this year it might well have found no.1 spot.
Unless I have a similar experience to Divinity Original Sin and find myself loving the game up until the point when I don't anymore. The first half of Divinity Original Sin, in and around Cyseal is by far my No.1 gaming experience of the decade, however, the second half is so tedious I barely managed to force myself to the end, the second half of the game not even making my top 20 in most likelihood. And Pathfinder is a very long game, so I'll have to prepare myself psychologically for a 6 month one-game run before playing it.
I have lots of honorable mentions and loads of games I feel guilty not mentioning, but then I guess so would anyone when being given a choice of just 3 for a decade.
I'm also curious about The Great Gias that both HiddenX and Carnifex rate very highly, another mammoth game.
So I wouldn't claim that my choices are good fits for GotD in a general sense, but they are most certainly my picks and all are games which most certainly helped me recover my love for gaming after the indescribable horrors of Dragon Age 2 and the ever more reduced choice in the gaming market as a whole.