Overpowered CPU and excessive motherboard. you don't need that high end of a CPU for games. An i5 2400 will save you $100 and you wouldnt be able to tell the difference for games or most applications. That is actually a fairly poor choice of CPU for price/performance. See here. There is only a 5% performance gain for the $100 price difference.
Thats a good power supply, Corsair makes some of the best, but you dont need 750 W. 650W would be plenty, and you could still add another graphics card and a couple HDD's if you wanted to later on. My system, which is very similar to what you have up there, uses under 450W when at max CPU/GPU usage.
There is practically no point to overclocking an i5 or i7 for gaming, except to post to forums about how awesome you are for being able to mess around with the voltages in the BIOS. You could easily save $200 on the CPU/mobo.
Also, that case is fuckin ugly =P. I like the Lian Li cases myself. Something like this is more practical, and much better construction.
Good HDD, not sure why you chose 6GB of RAM when you could get 8GB for about the same price.
That cooler is probably unneccessary, unless you absolutely insist on OC'ing.
