For gaming purposes, you'll want a quad-core processor at a minimum. Intel Core I5-4650K would be ideal if you can afford it. Otherwise, look to lesser quad-core Intel processors or look to the AMD FX6xxx series processors.
GPU will again depend on what you can afford. At a minimum for gaming, I recommend the latest generation graphics card from either AMD or NVidia; where the second numeral of the model number is at least a "6". For example: GTX760, HD7670, GTX770, R9 270, etc...
-Wolf sends