1500 to 2 grand? Jeez, you can build a fucking rocket ship for that.
Quite a few of your components are way too expensive, tbh. You can get cheaper ones that will only affect your performance by 1 or 2%.
Let's start with the processor. i7 is terrible, terrible overkill. Get the i5-2500K. It is simply the BEST gaming processor, as you can overclock this thing to literally absurd heights.
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115072Note, there is a reason that it gets 5 eggs...
219.99
Cooler. You'll have to decide whether you want quiet or whether you want to overclock. Other than using liquid, you can't have both. I got this one:
http://www.newegg.com/Product/Product.aspx?Item=N82E16835103065and it cools like a champ, but it does produce a bit of noise at 100% RPM. Nothing terrible, but you can hear it. You can install some software to lower it to 75 or even 50%, at which point it's whisper quiet, but do not try to overclock it when you're running at 50%. (Actually, to be honest, it'd probably still be fine, but that's kinda asking for trouble.)
It's 20 bucks right now! TWENTY BUCKS!
Mobo : Yours seems fine. I like Gigabyte boards well enough. When I went to buy mine, I just had a hard time finding a board where not every third review said something like "stability issues" or "memory doesn't work" or shit like that. Mobo quality has really gone downhill the last few years. The one I got doesn't seem to be made anymore, so basically pick your poison, I guess.
OS HD
I wouldn't go with 256GB for your OS HD, it's crazy to spend that much money on a drive you'll only use like 50 GB of. Go with a 64GB one, or if you want to not be on a space budget as much, a 128 GB one. Then buy another 128 GB to put your most played Steam Games on, and rejoice at the reduced level-loading times.
Also, that one seem to be the slow variety. Get one of the Sata3 / Sandforce 2 SSDs, as the read speed is dramatically better. This one is a beast:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820139599(I will say, though, that once every month or so, my computer will whine at me that it can't find a boot drive. For whatever reason, the BIOS will not recognize the SSD. I turn it off for a few minutes and turn it back on and the problem goes away. Not sure if it's the SSD or my mobo (I actually suspect the latter.))
I've upgraded the firmware and it hasn't happened since, so who knows.
This thing is expensive, I know. Speed costs money, but if you're going to go SSD for your OS disk, go all-in.
Data HD:
Eh, whatever. There's basically no difference between the big HD manufacturers.
GPU:
A GTX660ti gets like 98% of the performance of the GTX670, for 100 bucks less. That's straight cash, homey! I got the MSI Twin Frozr one, and I never hear it. Ever.
PSU:
850 Watts is overkill and a waste of power. 650 Watts is more than plenty, and quite frankly, so is 550 Watts unless you plan to hang 14 devices in your box or go SLI GTX680s. Do your energy bill a favor and get a 650W one, that way you're not turning extra watts into needless heat.
I got this one and it works just great, but some people have been less fortunate.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817151088Whatever you get, make sure you get a fully modular one, so you're not stuck with trying to find a place to stuff those 12 extra power cables you don't use.
Memory:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820233186Get the low profile memory. You will bless me when you see that your CPU cooler is hanging over your DIMM slots...
Case:
That's purely personal preference, but I will say that this case has been the easiest case to work with EVER:
http://www.newegg.com/Product/Product.aspx?Item=N82E16811352007I think my build comes around to $1250 (off the top of my head) and it'd probably run maybe 3% slower than what you suggested, and will actually boot and run a tad snappier in Windows because of the faster SSD.
Really the two things I would recommend against is the CPU and GPU. You're paying $200 extra for stuff that's just not noticeably faster.
Creston