This is the build you should get. $550 after rebates and $600 before rebates.
+ 6 Core FX 6300 CPU.
+ Asrock Extreme 4 Motheboard with good overclocking potential and nice features.
+ AMD 7950 is one of the best GPU's currently and is third most powerful only after the Titan (and Nvidia 780) and the 280x (or the 770).
+ 8GB RAM is ample for gaming.
+ 1TB HDD space is ample for storing just about anything a gamer needs.
+ NZXT Source 210, neat and easy to work case from NZXT, a well known case manufacturer.