Half Life 2 is indisputably one of the finest games ever made. The story itself is really cool when you take the series into consideration. During the game, its pretty typical alien occupation thing. Its how Half Life 2 presents that story that is stunning. Its something u need to play to believe.
I got my copy via Steam using a promotion coupon I got from AMD. I DLed and installed Steam, created an account, entered the key on the coupon, and bingo, i was ready to go (after a few hours waiting for download and verification)