Depends on your GPU. Generally if u need just a budget PC u don't even need to spend 500 bucks.
PCPartPicker part list:
http://pcpartpicker.com/p/3Pqrg
Price breakdown by merchant: http://pcpartpicker.com/p/3Pqrg/by_merchant/
Benchmarks: http://pcpartpicker.com/p/3Pqrg/benchmarks/
CPU: Intel Core i3-4130 3.4GHz Dual-Core Processor ($113.98 @ SuperBiiz)
Motherboard: Gigabyte GA-B85M-HD3 Micro ATX LGA1150 Motherboard ($67.24 @ Amazon)
Memory: A-Data XPG V2 8GB (2 x 4GB) DDR3-1600 Memory ($66.99 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($54.43 @ OutletPC)
Case: Thermaltake Commander MS/I Snow Edition (White/Black) ATX Mid Tower Case ($37.99 @ Micro Center)
Power Supply: Corsair Builder 600W 80+ Bronze Certified ATX Power Supply ($54.99 @ Micro Center)
Optical Drive: Asus DRW-24F1ST DVD/CD Writer ($14.99 @ Newegg)
Total: $410.61
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-05-23 10:57 EDT-0400)
or use i5 solution to spend all ur 500 bucks.
PCPartPicker part list:
http://pcpartpicker.com/p/3PqtR
Price breakdown by merchant: http://pcpartpicker.com/p/3PqtR/by_merchant/
Benchmarks: http://pcpartpicker.com/p/3PqtR/benchmarks/
CPU: Intel Core i5-4690 3.5GHz Quad-Core Processor ($199.00 @ Amazon)
Motherboard: Gigabyte GA-B85M-HD3 Micro ATX LGA1150 Motherboard ($67.24 @ Amazon)
Memory: A-Data XPG V2 8GB (2 x 4GB) DDR3-1600 Memory ($66.99 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($54.43 @ OutletPC)
Case: Thermaltake Commander MS/I Snow Edition (White/Black) ATX Mid Tower Case ($37.99 @ Micro Center)
Power Supply: Corsair Builder 600W 80+ Bronze Certified ATX Power Supply ($54.99 @ Micro Center)
Optical Drive: Asus DRW-24F1ST DVD/CD Writer ($14.99 @ Newegg)
Total: $495.63
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-05-23 10:59 EDT-0400)
Have no idea about ur GPU so I pick up a PSU capable for up to GTX 770 or R9-280X level. Also this PSU is capable for ur future GPU update.