Most of my time spent with 2010's NieR was spent staring slack-jawed at the screen. Between its bizarre genre shifts, oppressively dark anime-esque narrative, and patchwork mechanics, there was a fascinating and bizarre game. It indulges itself in almost every flaw and merit allowed for a video game, all while weaving a weird tale about humanity's extinction and your role in it. It became one of the few games that I've played that has aged as well as Metal Gear Solid 2 in terms of what it's actually doing as a video-game.
(*this is your spoiler warning*)