This is the best game in the series.
First off, there is a huge graphical difference between the 360 version and the other two. Anyone who does not agree with this simply does not have a high definition TV to display the beautiful visuals that this game offers. The audio is great, especially Stephen Dorff's voice acting which makes the PC version embarassing. The value is great because you get two games in one package, pluse multiplayer is pretty fun and let's not forget that you can create your own maps.
If you want a great FPS that you will be playing for a while, check this one out. The single player campaign is easily going to take you 20-25 hours to complete so that alone is worth the $60.00.