Alright. So this is what I think looks good for the price-point stated. It does go about 15 dollars over budget, however I assure you it is 15 dollars well spent!
PCPartPicker part list /
Price breakdown by merchant
CPU: AMD FX-8350 4.0GHz 8-Core Processor ($164.99 @ NCIX US)
Motherboard: MSI 970 GAMING ATX AM3+ Motherboard ($98.88 @ OutletPC)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory ($54.89 @ OutletPC)
Video Card: EVGA GeForce GTX 750 Ti 2GB Superclocked Video Card ($119.99 @ Newegg)
Case: Cooler Master HAF 912 ATX Mid Tower Case ($49.99 @ Newegg)
Power Supply: Corsair CX 430W 80+ Bronze Certified Semi-Modular ATX Power Supply ($25.00 @ Newegg)
Total: $513.74
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-07-21 11:23 EDT-0400
Now I'll tell you why I picked these parts.
CPU: The AMD cpu I picked is relatively inexpensive for a CPU and provides some great performance in game. It has eight cores and comes stock clocked at 4.0 Ghz.
Motherboard: MSI is a great brand especially in motherboards and this one will provide the opportunity in the future to overclock if he is so inclined.
RAM: I picked eight gigs of G-Skill RAM because I run with eight gigs...and most games these days won't need too much more than that.
Case: The HAF 912. What can I say about it. It has great airflow, so while it may not be the quietest case it is very efficient, and efficiency is key.
PSU: Corsair Power supplies are great. In fact I have one in my machine right now! It is reliable as all heck too.
I didn't include an SSD in this build because at this price-point, it would just make it over budget.
Let me know what you think!