This is the Game of the Year 2011. Buy this game! It's worth your money.

There is a reason why this game is free: because it's simply not worth a cent.

As some say, Team Fortress 2 is the best FPS of all time, I do have to disagree with them. The reason I love Valve is because of Half-Life series. And God, where do I begin with Half-Life 2? The story is a beauty, the environments are awesome yet varying. The characters and enemies are memorable and it has the iconic crowbar and headcrabs. Not just being as realistic as possible, in this game you can kill enemies with thrown objects, thanks to the improved physics engine. Even the AI is some of the best ever made. The Combine Soldiers actually take cover, try flush you out with grenades and attempt to flank you in groups. No doubt, Half-Life 2 is the best and most classic FPS game ever made. With only a very minor flaw to note, if I had to criticize: the hardest difficulty in the game does not seem hard enough. It could had used one step higher difficulty. Regardless, if you don't own this game yet, you really should! Half-Life 2 deserves a full 10/10