Call of Duty: Modern Warfare 2 (2009)

the easiest way to reach 8 stars is to stick to the Alpha set of Spec Ops. the pit, the snowmobile races, and the first wave defense are probably the easiest to get 3 stars on. and you will need to get multiple stars on at least a few missions, as you cant unlock the second set of missions until you get this achievement. the best way to beat missions on the harder difficulties is just take your time and reload as often as possible. the worst thing to happen is to get caught with an empty clip.