Came out under $1500, first brand new build from scratch in 5 years( my last build was athlon 64 3000+ socket 939...with radeon x800xt lol...still plays Wow pretty good). Been using iMac for 2 years(for logic and Pro Tools) and loved its simplicity and OS but it absolutely sucked when it comes to gaming (with low settings and 1280x720 resolution) so decided to build a new gaming rig.
Case: Cooler Master HAF 922
CPU:Core i7 - 860
Cooler: Noctua NH-U12P
Motherboard: Gigabyte GA-P55A-UD4P
RAM: Corsair XMS3 DDR1600 2GB x 2
Video Card: Radeon HD5870
Power Supply: Corsair 750TX
CD/DVD burner: Cheapest LG 22x i could find
HD: SAMSUNG Spinpoint F1 1TB
Monitor: Already got 55 inch 1080p samsung
Keyboard/Mouse: already got logitech wireless keyboard and laser mouse.
OS: Windows 7 Professional
I recently completed a build using the older version of the Gigabyte GA-P55-UD4P motherboard, and it has been rock solid and joy to use. Windows 7 automatically loaded the latest versions of all of the drivers, and I only had to load the Realtek audio drivers. I decided not to load any of the Gigabyte software because I didn't intend to use any of it, but that is just my preference.
I would stick with the Corsair 750TX -- this is a really good power supply.
I see nothing wrong with the Noctua HSF. This unit is extremely quiet and although it is little more expensive than some other HSFs, it has an excellent repution for reliability and performance.
If you live near a Microcenter store, you can pick up an i7-860 CPU for $230, or an i5-750 CPU for $150. However, this deal is only for in-store pickup, not mailorder. I am guessing there marketing strategy is that they can sell you other things, if they get you in the store. That strategy didn't work with me, because I was in a hurry, and just had time to pop in the store to pick up the processor.