500- 650$ budget for low- medium gaming pc

I need a new gaming pc. I already have a keyboard and mouse. Thanks to FinneousPJ for the format.

Approximate Purchase Date: Within 6 months.

Budget Range: $500- $600 would be best but I can swing $650.

System Usage from Most to Least Important: Gaming, surfing the web, and watching movies.

Are you buying a monitor: Yes



Parts to Upgrade: RAM

Do you need to buy OS: Yes

Preferred Website(s) for Parts: None

Location: Minnesota, USA

Parts Preferences: by brand or type (e.g.: I would like to upgrade to Intel CPU)

Overclocking: Maybe

SLI or Crossfire: I don't know what that is so probably not.

Your Monitor Resolution: 1280x1024 should be ok but if you recommend a different resolution I might change it.

Additional Comments: I don't have that much money so it needs to be sort of future proof and it would be nice if it was semi- quiet.

Why Are You Upgrading: I am on a really bad laptop right now and I can barely run minecraft on low settings and LOL on low settings (they both get about 20 fps)
 
there will be new parts and updated price within the next 6 months

if you want to know what is $600 build, here it is

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: AMD FX-6300 3.5GHz 6-Core Processor ($117.97 @ SuperBiiz)
Motherboard: MSI 970A-G43 ATX AM3+ Motherboard ($54.99 @ Newegg)
Memory: Crucial Ballistix Sport XT 8GB (2 x 4GB) DDR3-1600 Memory ($56.99 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($59.99 @ NCIX US)
Video Card: MSI GeForce GTX 650 Ti 1GB Video Card ($89.99 @ Newegg)
Case: NZXT Source 210 (White) ATX Mid Tower Case ($35.97 @ Amazon)
Power Supply: Corsair CX 500W 80 PLUS Bronze Certified ATX12V Power Supply ($34.99 @ Newegg)
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) ($84.98 @ OutletPC)
Monitor: Acer G236HLBbd 60Hz 23.0" Monitor ($109.99 @ Amazon)
Total: $645.86
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-11-09 17:31 EST-0500)