Deus Ex is ten great games in one, as your in-game choices dramatically affect both how you play and where the dystopian sci-fi story takes you. Maybe you plotted a stealthy ninja route through the intricate levels, while your friend blew a hole through the front door and shot everybody in the face. Or maybe you hacked security cameras and smooth-talked your way into restricted areas, while your friend blew a hole through the front door and shot everybody in the face. Goddammit, Eric! Show some finesse!
As much fun as we had playing Warcraft II, every game was essentially just a race to get Ogre Mages; because nothing beats bloodlust. Nothing. Warcraft III introduced hero units to multi-player games, which were only offered in the campaign of previous titles. It allowed a fresh multiplayer experience by departing from the Starcraft/Warcraft formula, and the focus on heroes allowed Blizzard to create arguably its best campaign ever. Each of the four playable races had their own story mode, including an extra orc campaign that acted as the prologue. And whereas previous games painted the Horde as blood thirsty savages, Warcraft III fleshed them out and allowed gamers' to be more sympathetic to their plight. The overarching story of Arthas' fall was a refreshing break from the cookie cutter story of noble humans defeating evil monsters. For once, a human was to blame for what was wrong with Azeroth. Down with the Alliance!
I could kiss the genius that decided to take Warcraft and put it in space. If that wasn't the greatest idea ever, it's up there. Blizzard revolutionized the RTS genre with the early Warcraft games, but they perfected it with Starcraft. It's the game that put competitive gaming on the map, and despite being released over a decade ago, it's still played on the professional level. Blizzard introduced its Battle.net system of multiplayer gaming with Diablo in 1996, but it was Starcraft that really showed the service's full potential. Connecting to a friend for multiplayer Warcraft II was a herculean task; and God help you if your mom picked up the phone while you were trying to make a connection. With Starcraft, you had access to an entire community that offered games with up to eight players. Plus, three races!
Considering it used to look like this, it's amazing that TF2 ended up with such an awesomely light-hearted visual style. The animation is so slick-looking and its dialogue so naturally funny, it's easy to forget you're here to perforate, incinerate and pulverize the opposing team into a bloody mess. TF2's diverse class system and hyper addictive gameplay are more than enough to keep you plugged into Steam, even if the whole thing is just a large-scale haberdashery scheme.
Fallout 3 is huge. It's insane how much game is crammed into the DC Wasteland. You could theoretically play it forever trying to finish every last mission. I was 40 hours in and at the level cap before I started pursuing the main storyline in earnest. Beyond that, the world is interesting and immersive. The tone is a weird combination of nuclear death and '50s optimism. Your decisions have real weight. Some games say your decisions have weight, but Fallout straight up lets you blow up the main town if you opt to lean renegade. On top of all that, the story is great, from being born in a bomb-proof underground vault, to watching the giant robot Liberty Prime demolish your enemies with lasers. New Vegas is great and hilarious, but Fallout 3 is still the best Fallout to date.