AMD Build:
PCPartPicker part list:
http://pcpartpicker.com/p/krsY23
Price breakdown by merchant: http://pcpartpicker.com/p/krsY23/by_merchant/
CPU: AMD FX-8320 3.5GHz 8-Core Processor ($139.99 @ Newegg)
CPU Cooler: Thermaltake CLP0608 99.1 CFM CPU Cooler ($49.50 @ Amazon)
Motherboard: Gigabyte GA-990FXA-UD3 ATX AM3+ Motherboard ($104.99 @ NCIX US)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory ($78.98 @ OutletPC)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($54.98 @ OutletPC)
Video Card: MSI Radeon R9 280 3GB TWIN FROZR Video Card ($195.91 @ Newegg)
Case: Thermaltake Commander MS-I Epic Edition (Black/Red) ATX Mid Tower Case ($39.99 @ Micro Center)
Power Supply: EVGA SuperNOVA NEX 750W 80+ Bronze Certified Semi-Modular ATX Power Supply ($49.99 @ NCIX US)
Optical Drive: Samsung SH-224DB/BEBE DVD/CD Writer ($15.00 @ Newegg)
Total: $704.33
Prices include shipping, taxes, and discounts when available
Intel Build:
PCPartPicker part list:
http://pcpartpicker.com/p/kQvKNG
Price breakdown by merchant: http://pcpartpicker.com/p/kQvKNG/by_merchant/
CPU: Intel Core i5-4690K 3.5GHz Quad-Core Processor ($225.98 @ SuperBiiz)
Motherboard: MSI Z97 PC MATE ATX LGA1150 Motherboard ($89.99 @ Micro Center)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory ($78.98 @ OutletPC)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($54.98 @ OutletPC)
Video Card: MSI GeForce GTX 760 2GB TWIN FROZR Video Card ($184.99 @ Newegg)
Case: Thermaltake Commander MS-I Epic Edition (Black/Red) ATX Mid Tower Case ($39.99 @ Micro Center)
Power Supply: EVGA SuperNOVA NEX 650W 80+ Gold Certified Fully-Modular ATX Power Supply ($49.99 @ Newegg)
Total: $724.90
Prices include shipping, taxes, and discounts when available
I also included a nice surprise, an awesome black/red colour scheme, and it did not impact on the cost or performance of your build at all so don't worry about that. There would be no cost difference if I didn't have the colour scheme so I thought since it would be the same price may as well have an awesome colour scheme build.