$400-500 for all three components? if so, then I would go with:
CPU/Mobo combo: 2500k with Asrock z68 gen3http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.1226683
this GPU: radeon 7870 from MSIhttp://www.newegg.com/Product/Product.aspx?Item=N82E16814127722
With these, you should get close to maxing out all of your games.
Things to consider are: which case do you have? and what is your PSU?