What you mean "on this site"? The staff or the users?
Regardless, this site has always been Nintendo land, do Sony games really win got here every year? Can you please show it to me as I find it extremely hard to believe.
Actually I recall something completely different, specially user related.
Last year was RE: 2 beating out Fire Emblem 3 Houses.
2018 was God of War beating out Smash Ultimate.
2017 was BOTW beating out Horizon Zero Dawn.
2016 was Uncharted 4 beating out Last Guardian.
2015 was Rocket League. No runner up beyond this point.
2014 was Smash Wii U.
2013 was Mario 3D World.
2012 was Journey.
2011 was Skyrim.
2010 was Mass Effect 2.
2009 was Uncharted 2.
2008 was Little Big Planet.
2007 was BioShock.
Out of 13 years, 5 Sony games, 3 Nintendo, and 5 other. Nothing really jumps out to me as questionable enough that I'd accuse anyone of bias, although I don't think Uncharted or 3D World were really GOTY worthy... although they did come out in relatively weak years. Also think that Galaxy 2 should have won over Mass Effect 2, despite how good ME 2 was, but that's just me.