9. Portal 2
Along with creating one of the most overused memes in internet history, which I promise not to quote here, the original Portal was one of the smartest, funniest games ever made. The puzzles were ingenious, the tone was darkly comedic, and the main villain, GLaDOS (a hilariously malevolent AI), remains one of gamings greatest antagonists. Its one of the most important games of the past generation, so of course gamers were cautiously optimistic when a sequel was announced. Turns out there was nothing to be cautious about; Portal 2 is a perfect sequel that improves upon the original in every way. The puzzles were trickier, the dialogue was funnier, the cake was tastier (damn it!), and the story was deeper. Its the latter point that truly makes Portal 2 shine, as Aperture Laboratories developed a real sense of history, and GLaDOS was given a genuine character arc. Halfway through the game, GLaDOS switches from antagonist to reluctant sidekick, as she teams up with Chell (the player) to defeat the adorably stupid, improbably evil Wheatley. As they traverse the facilities, recorded messages from deceased Aperture founder Cave Johnson reveal GLaDOSs surprisingly tragic backstory. Before his death, Cave Johnson ordered that the mind and personality of his assistant, Caroline, be uploaded into the AI that would become GLaDOS. Chell and GLaDOS fight Wheatley in one of the most inventive boss battles in gaming, one that requires lateral thinking rather than a quick trigger finger. The conclusion is fittingly over-the-top, as Chell uses a portal to send Wheatley to the moon where he must drift through space for all eternity with a mentally unstable personality core. GLaDOS reclaims her throne and is uncharacteristically relieved when she discovers that Chell is safe. This newfound compassion is thanks to Caroline, who GLaDOS decides to delete from her personality so she never feels compassionate again. But as Chell is being safely transported out of the facility, its obvious that GLaDOS has changed, and that Caroline will always be a part of her - whether she likes it or not.