For all of you who rated it 1 without even playing it.

User Rating: 9.5 | Call of Duty: Modern Warfare 2 PC
Sure it doesnt have dedicated servers but the multiplayer is fantastic. I was extremely skeptical and annoyed at the announcement of non dedicated servers/mods and things but please please.. please dont knock it until you've tried it. It is an awesome well rounded experience and is a huge step up feature and gameplay wise from the original CoD 4.
Unfortunatly the single player lets this game down a tad. Its extremely fast pace and it feels as if you dont have enough time to enjoy the surroundings and story line, it is easy to miss alot of things.
Though the game makes up for it all in sheer Visual Candy.

I am running the game on a 545 X2 3.0GHz AMD, 3Gigs of DDR3 and a 1950xtx ATI. I can run this game on full and it still runs smooth. The character Detail is amazing as are the weapons. Alot of times and effort has gone into this game and sure as anything they have pulled it off.

So once again to not knock it until you have tried it.