[First Build] ~ 900 Dollar gaming rig

A couple suggestions:

G.Skill PI Black
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Better RAM, lower voltage.

Gigabyte UD3P
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
The extra cash you spend on this one would be worth it. If not that, then this:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

The Corsair 850TX is a great PSU. If you need to save though, the 750TX would.... Ah, never mind you are getting the combo deal on the PSU/Case.

Good overall build.

Only comment would be that the Q6600, although much loved is getting on a little, have a look at some of the newer 45nm chips Q8xxx (I think)

i like the antec 900 case better and it's 10 bucks cheaper in this combo with that mobo:

http://www.newegg.com/Product/ComboDealDetails.aspx?Ite...

if you plan to overlock get this:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

+1

They're faster and run cooler.

Just for more variety I post an AMD build, just for the record I know little of AMD's besides looking at them for the past day or 2 so if you do go with what I post get it double checked by someone else. And I just slaped this build together in a few minutes last night just to get a rough idea of what it would cost me to do an upgrade. Oh and if you look around you can probably find better deals + bundles.

AMD Phenom II X4 810 2.6GHz 4 x 512KB L2 Cache 4MB L3 Cache Socket AM3 95W Quad-Core Processor - Retail $169.00
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

ASUS M4A78T-E AM3 DDR3 AMD 790GX ATX AMD Motherboard - Retail $139.99
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Western Digital Caviar Black WD6401AALS 640GB 7200 RPM 32MB Cache SATA 3.0Gb/s Hard Drive - OEM $79.99
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

SAPPHIRE 100258-1GL Radeon HD 4850 1GB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail $161.99 (2 of these for crossfire)
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

PC Power & Cooling S75QB 750W ATX12V / EPS12V SLI NVIDIA SLI Certified (Dual 8800 GTX and below) CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Retail $99.99 after sale and rebates
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

G.SKILL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Dual Channel Kit Desktop Memory - Retail $69.99
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Subtotal: $898.94
Tax: $65.17
Total: $964.11

But you still need a case, and accessories, but thats more personal preference so I leave that up to you. And if you plan to OC pick up a heatsink for the CPU I recomend one but I know nothing really AMD chips besides what I learned in the past few days which so far in my opinion they look pretty nice for price/performance wise.