The Witcher 3, easily. Overall, given the sheer amount of games being published, there have been relatively few truly great games, the overly heavy focus on production values and the constant reusing of concepts, gameplay and styles have caused it all to become rather stagnant for me. Seeing the table turn somewhat feel good though, some industry veteran behemoths are getting flack, finally, and their ways are causing problems at long last and will need resolving (talking about EA, Blizzard etc.).
End of 2016 hardware sales:
Wii U: 15 million. PS4: 54 million. One: 30 million. 3DS: 64.8 million. PSVita: 15.2 million.