for those games a i3-2100, phenom2 980, a8-3870k is also good.
mw2,mw3 use very little cpu+gpu power at extra settings at 1920x1200 (filltering off).
But you have budget around 200 then i5-2550k is a good option to consider for all future games.
To get 75fps at those settings, atleast a 6770 is required.
Which gpu you have/planning?