The Witcher 2: Assassins of Kings may be draped in the cloak of a brutal fantasy world filled with monsters and magic, but it offers an interesting reflection of real-world problems. It's a political drama where those in command are governed by fear and uncertainty. It shines light on racism and sexism in ways that shows developer CD Projekt RED is unafraid to push narrative boundaries beyond most games in its class.

Based on the book series from Polish author Andrzej Sapkowski, The Witcher 2 goes worlds beyond the 2007 original title in almost every conceivable way (though there is some contention with the game's ending). Combat is completely overhauled--and after a few balance tweaks soon after release, it's satisfying to the point of perfection. The game can be unapologetic in its command for your attention and skill, pushing aside a generation of games marketed to the era of players raised by handholding execution.

Read more: Why The Witcher 2 was our Game of the Year »

With Portal, Valve took the mechanic of shooting--something we're very familiar with--and used it in a whole new fashion. Using a gun that opened portals, Valve created a geometry-based puzzle game, the object of which was to use the openings to navigate increasingly challenging test chambers. With that starting point established, Portal 2 hits the ground running.

Portal 2 tricks you into thinking you'd never leave the unfriendly confines of the Aperture Science labs. Then the game blossoms, blowing down the very walls needed for its portals and opens up into a fantastic adventure. Breaking out of the test chambers feels liberating, answering the question: "what could I do with this portal gun in the world outside a test chamber?"

Read more: Why Portal 2 made our 'Top Five' »