1. Team Fortress 2 (PC)
Sid Meier once famously defined a game as "a series of interesting decisions." But game development is also a series of interesting decisions. Valve Software made one such decision early in the development of Team Fortress 2: Originally the game was going to use realistic soldier models, wearing camouflage and using modern weapons. Early response was good; people were excited.
But the gameplay for Team Fortress 2 is fast, crazed and over-the-top. That old art style just didn't work with the style of game the designers wanted to create. And so Valve scrapped everything to start from scratch and made one of the best decisions in recent memory: to make Team Fortress 2 look like a living cartoon, like a cold war propaganda print come to life. Larger-than-life characters, oversized weapons, and distinctive hand-painted environments abounded. Valve created one of the most distinctive-looking games ever.
But this award isn't about eye-candy. That unique visual style is the perfect complement to outstanding multiplayer gameplay. You can see a player from across the map and instantly identify their distinctive silhouette: "That's a Heavy Weapons Guy on the Red Team." "There's a Blue Spy carrying the intel." No matter how intense and insane the action gets, you can instantly parse what's happening on the screen.
The entire Team Fortress 2 game design represents one fantastic decision after another. Every class is tweaked and massaged until it plays an indispensable role for the team. TeamFortress 2 is essentially a defensive game, so the designers added little hooks to enable players to spectacularly break a stalemate. For example, Medics and the players they're healing can become temporarily invincible, a game design decision that breaks stalemates and periodically throws the game into a delightfully chaotic uproar.
Touches like that contribute to the expert pacing of the game. Good single-player games always struggle to give players moments of tension followed by breaks to catch their breath. That's tough to do in multiplayer, but Team Fortress 2 succeeds. Quiet moments of repairing turrets or setting up sticky-bomb booby-traps are disrupted by sudden bursts of frantic firefights. Maps are claustrophobically tight and players are always an instant away from a conflict that'll determine the outcome of the game.
This game is so good you'll regret tearing yourself away for bathroom breaks.
And of course, all the essentials are there: the gameplay is silky smooth, the maps are well-designed, the controls are responsive, and you get lots of visual feedback on what's happening. This is absolutely the best multiplayer experience of the year, and that's saying something, given the strength of the other games on this list.
[We should note that although the Xbox 360 version of TF2 is solid, the PC has a much larger player-base and we're specifically giving the award to the PC version. Unfortunately the PS3 port is a little too rough for our tastes, chopping up the framerate during intense battles and screwing up voice support. Look for us online: We'll be running the Intel, baseball bat in hand.]