Julius Terrell said:
I'd also up the amount RAM. 8 gigs means shit now-a-days.
Classic I-don't-know-what-I'm-talking-about.
Unless you're running a virtual network on your machine or undertaking some heavy editing or compositing, 8GB is quite fine. The whole notion that we've landed in a time where we need a minimum of 16GB is total nonsense.
See here, my PC running a custom game of League of Legends, the opening cinematic for Sleeping Dogs, Adobe Photoshop with my portfolio opened and a new document to paste the screenshot into, iTunes, Skype, Steam downloading a game, Adobe Illustrator with one file open, Chrome with 6 tabs open, including a 10-hour HD video currently playing.
Didn't even hit 60% usage. 8GB DDR3 will do fine. I prefer 8GB of a high quality over 16GB of el cheapo 1066mhz that isn't gonna help you, but cost you more. The only reason I even have an i7 is because of the HT feature missing from the i5 series at the time as I do dabble in graphics and encoding/editing of footage.
@OP: As long as you're not using two or more top notch GFX cards, that PSU is fine. I'm running an i7 2600 @ 3.8gHz, Corsair Vengeance 1600mHz 8GB DDR3, an OCed EVGA GTX580 2GB, 3 harddisks, 6 USB periphals, 6 fans inside the casing and an iPhone4 charging on a Corsair 450W PSU.
A lot of people running their mouth telling you you need a 600+ PSU, dozens of RAM and a super expensive graphics card to fare well in todays gaming market are full of it.
OP, I suggest switching to Windows 8 and installing a little extension called Start8 ($5) to restore the Windows 7 Menu to Windows 8 with more features to boot. Windows 8 is a lot more snappy and responsive and runs lighter as well on your hardware. I have not encountered any programs other than LA Noire (which is a poorly coded piece of crap as it is when it does 'run' on Win7) not to work under Windows 8.
I don't know your budget or your storage needs, but after I got my first SSD (a different type of harddisk to put it simple where you pay for speed, not size) I was and still am hooked. It makes working with things so much faster. I'd opt for a 500GB 7200RPM as a secondary disk if budget is a problem and grab a 128GB SSD, like the Crucial M4.
You really don't need that 6-core for gaming. Quad will suffice. Save yourself the costs. No programs other than video encoders really address your other cores. Hell, most games only address two. Whatever CPU you decide to get, you can get the cheaper ones of any line. Games aren't CPU-intensive and it isn't gonna matter much if you pick that i5 with 3.2gHz or the one with 3.6gHz for $40 more for example. (inb4 someone posts benchmark results where the latter gets 2 whole FPS more on a worthless stress test)
I prefer Nvidia cards for CUDA (video encoding and also playback) and their drivers. I've owned more than one Radeon, and drivers have been an issue more than once, forcing me to downgrade or adjust some crap to deal with games that were considered 'older' (textures poofing on me on Halo 1 and odd polygon issues in Perfect World) or too new. I also found the Radeon anti-aliasing to be more grainy than Geforce cards. But in the end it's all preference, and for a few bucks less you can get similar performance to an Nvidia card with the same specs.