Blizzard's latest real-time strategy game, StarCraft II: Wings of Liberty, was launched in a tough multiplayer spot with a lot to live up to. Its predecessor was still being played by the hardcore and is a national sport in South Korea. On the other side of the coin, the RTS genre had become more and more niche over the years since the company's last release, Warcraft III. Blizzard succeeded in releasing a game that was eSport ready on day one, but was also fun for more casual players. The innovative leagues and ladder system offers meaningful matchmaking and rankings to all but the most skilled players, while custom games and comp stomps sweeten the deal. With two expansions on the way and more tournaments than we can count, StarCraft II is well on its way to being played for the next ten years just like the original.
Runner-up: Assassin's Creed Brotherhood
Brotherhood's multiplayer rewards planning and strategy in a way that is extremely satisfying. It shatters the multiplayer mold set by run-and-gun games like Call of Duty and makes patience the player's most powerful weapon. There are few thrills in multiplayer gaming equal to carefully stalking your playter-controlled prey, while the constant danger of a blade to the back hangs over your head.