Rightly dubbed as the BEST. GAME. EVER.

User Rating: 10 | Half-Life 2 PC
This probably is one of the first FPS games I've ever played, Half-Life 2 blew me away with its intense action, deep storytelling, and insane modability. Even though the graphics are outdated, it was probably top-of-the line in 2004, when it was released. Nonetheless, the visual style is great, the enemy design and AI is kick-ass, and the developers, Valve, are true visionaries. They set forth the concept of FPS gaming and blew other shooters out of the water when they released the original Half-Life six years ago.
Just the fact that you play as a scientist with almost no combat experience instead of a soldier or a gang member makes you feel all the more bad ass. This along with the fact that every archetype of video game enemy is trying to attack you (aliens, robots, zombies, and guys with guns) makes it all the more revolutionary and original. I've played through the game at least 10 times, and every play through, despite it being absolutely linear, is something to remember. I definitely recommend this game. You'd be joining one of the world's best game communities and you'd be buying a game by the world's best developers.