1. Portal 2
Developed by Valve Corp., Published by Valve Corp. and EA
This wasn't a difficult choice. Portal 2 is both the perfect game and the perfect sequel—it builds on and expands the world and mechanics of the first Portal without forgetting what made that game great to begin with. Its imaginative puzzles present the perfect amount of challenge, its difficulty curve is almost imperceptible, and its writing is hilarious, touching and charming in equal measures. Bottom line: it's impeccable. Now move along, folks; 2012 is almost here!