That's a pretty hard list to argue, though gaming is so broad that I'd really have to sit and think. Narrowing it down to five games excludes games that brought entire genres to life and set standards that would continue on forever. Like World of Warcraft, which more or less made MMORPGs accessible to the mainstream, or even Windows Solitare, a game that introduced many people who never noticed computer games to the world of casual time-killers. Angry Birds was the first game of countless kids born around 2010, and Guitar Hero brought forth a music game renaissance.
My line of thinking is the 70's could be defined by one game but after that it needs to become increasingly granular. 80's is no good, 80-85 and 86-90 seems more fair, or split the 80's into three sections.
Into the nineties it needs to be defined into shorter sections, after 95 it should probably go year by year, things happened so quickly. Jumping forward in time there cannot be one singular thing that defines a period because the audience is so big and genres, platforms or type of games have branched off into their own things and can be completely insular from each other.
Dark Souls have had a huge influence from big to small gameplay decisions that can be seen in many games, is that more important than King and their mobile games and the millions of old ladies that found out that playing games weren't just for their grandchildren? There might be more grandmas playing Bubblewitch than the combined total of people that have played Dark Souls. If you had asked the grandmas 10-15-20 years ago if they could ever be really into playing a video game and they would have said no, without hesitation. Something big happened there.
I like Dark Souls but I can't claim that old ladies with puzzle games are wrong or that someone playing horse mystery games should switch genre.
A visual illustration of my thinking would be a tree, growing from nut to stem, to thick stem, to the first branches and finally a big canopy of leaves from many, many branches. That's how games have evolved and that's the current state of games.
In conclusion, Polygon can go fuck themselves and if they felt the need to wax politically about the importance and impact of a game, socially and politically, they could have chosen Tetris like everyone else over the last 20 years.
In fact, I think Tetris should be codified as the best game ever made and it can't ever be changed. You might not think it is the best, I sure as hell don't, but that's just how it is now and Tetris will be at the center of everything like a north star. Where is Dark Souls in relation to Tetris? Not very close, obviously. Slime Rancher, closer to Tetris than DS but on the south side, etc, etc. At least we will have some common direction to refer to.