Overall the build looks really good. The only thing that I would change is to move to the Intel® Core™ i5-3570K so that I can overclock in the future. Should be able to just about anything you want with it.
If you don't plan to OC, then save a bit of money and get a H77 mobo. If you do, go with an i5-3570k with a CPU cooler like a Cooler Master Hyper 212 Evo.
For RAM, consider buying from Newegg because they usually have RAM on sale, and are cheaper in general. Their Gskill Ripjaws X series is a good one. Mushkin's Blackline and Crucial Ballistics are also very good too.
CPU: Intel Core i5-3570K 3.4GHz Quad-Core Processor ($214.99 @ Amazon)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($29.99 @ Newegg)
Motherboard: ASRock Z77 Extreme4 ATX LGA1155 Motherboard ($132.86 @ Newegg)
Memory: Patriot Signature 8GB (2 x 4GB) DDR3-1600 Memory ($50.77 @ Amazon)
Storage: Hitachi Deskstar 1TB 3.5" 7200RPM Internal Hard Drive ($83.98 @ Outlet PC)
Video Card: EVGA GeForce GTX 670 2GB Video Card ($399.99 @ Newegg)
Case: NZXT Source 210 (Black) ATX Mid Tower Case ($34.99 @ Newegg)
Power Supply: NZXT 650W ATX12V / EPS12V Power Supply ($84.98 @ Amazon)
Optical Drive: Sony AD-7280S-0B DVD/CD Writer ($16.99 @ Newegg)
Operating System: Microsoft Windows 7 Home Premium SP1 (64-bit) ($88.73 @ Amazon)
(Prices include shipping and discounts when available.)
(Generated by PCPartPicker 2012-08-02 17:17 EDT-0400)
someone suggested paying $20 more for an EVGA GeForce GTX 670 FTW so i could overclock in the future. is it worth it? i've never overclocked a computer before, when and why would i need to? is it just so i can increase the amount of time it's non obsolete?
someone else also said the NZXT PSUs were "sketchy" and i should get something else, any truth to that? if so what would be a good alternative?