Breath of the Wild - This game constantly bombarded you with things to do while giving you the pace to enjoy them in a sandbox way

My favourite of this decade would be Pokemon Black/White, but the one I've played the most is Skyrim.

Monster Hunter Tri

Indeed, they are not in direct opposition, but I often see folks comparing them - which is quite silly, they might both be designed as open world game, but ultimately fall into different genres and since BotW exploded and got its mainstream cult following (not unlike Skyrim so many years before), it is very common to see such comparisons.

But ultimately, they are very different games (though both designed for mainstream appeal), each with its own sets of freedoms and game mechanisms, and IMO both decent games, but also quite limited.

As much as I have loved PS exclusives, I have to say Witcher 3. I'm partial to 3rd person RPGs and this was the ultimate expression of that. Everything was done excellently in my opinion, be it technical or artistic (I came in a little later, so all the bugs had already been dealt with). CDPR obviously puts a lot of heart in what they do. The attention to detail and weaving such storytelling into the world, with well fleshed out and likable characters, choices that actually have effects, and whatnot. Greatness.

I wasn't sure whether to include this one in my honourable mentions; it's a 2010 release in the West, but came out in 2009 originally, in Japan.

i would have put skyrym up there, but recently i did a re evaluation of bethesda software and came to the conclusion we have been duped, into believing and falling for their hype. From the bugs, to the graphics, physics and AI, really outdated, long load times, encumbered, glitches, half decent story, dragons that look cheaply designed. Fell for the same fiasco in fallout 4, 76. Looking back, there was barely much fun in it at all, just more repetition. Would definitely avoild the enxt few fallout/elder games unless there is a complete over haul of the game design and a new engine built from the ground up only for next gen hardware.

Yeah I kinda agree, even back in 2011 I never understood why people were so full of praise for a game that couldn't run for 10 minutes without a glitch. It's just so damn janky.

Skyrim.
It set the bar for what I look for in open-world games, and what I want for in-game lore.

I played it for 105 hours my first run through, no glitches. That was on PS3. 

When I tried playing it on Xbox 360 to review Dawnguard and Dragonborn for the website, it crashed dozens of times in less than 20 hours. 

Everyone has a different experience and some people didn't experience many glitches; furthermore, sometimes the glitches aren't all that bothersome and I, for example, don't mind the occasional glitch if it means I get to enjoy such a serene, huge game. All these years later, I still love just relaxing and questing in Skyrim.