Is COD4 such a great game?

I was playing it at a friend's place b/c my comp cant support it, but the game is pretty intense. It flops back and forth between who your doing missions for so it adds a bit of variety to your game play experience. I died a lot and it sucked, but the action keeps you focused and on your toes. I even got killed by freaking dogs b/c I wasn't expecting them to run out.