I think you can do better.
1) Nothing wrong with the i5-2400, particularly if you will not be overclocking. But, a 2500K or a 3570K does not cost much more, and it gives you the option to overclock. The "K" suffix cpu's were designed by Intel to be overclocked by somply raising the multiplier from the default of 3.4 to 4.3 or thereabouts. A very nice jump for not much extra. If you live near a microcenter, they will sell you a 2500K for $170, or a 3570K for $190, the last time I checked.
2) You picked a very expensive $250 motherboard. For your purposes, ANY Z77 based $110 motherboard will do the job just as well.
3) For a gamer, the graphics card is much more important than the cpu. My rule of thumb is to spend twice your cpu budget on the graphics card as you do on the cpu. In this case, a $200 cpu deserves a $400 GTX670.
4) Regardless if you OC or not, I recommend including an inexpensive $30 aftermarket cpu cooler like the cm hyper212.
The stock intel cooler gets noisy when it needs to spin up the fan under load. The hyper212 with it's slow turning 120mm fan will be quieter, and keep your cpu cooler. And.. for the new builder, the backplate mount is much easier to do right than the Intel pushpin mounts.
5) The ram is good, but 1.5v ram does not really need high heat spreaders, or any at all. I suggest the low profile ares variant which costs a whopping $ 1 less:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
6) OCZ seems to have mixed opinions as to quality. My short list of quality psu's would include Seasonic, PC P&C, Antec, Corsair, or XFX. The GTX560ti needs a 500w psu, and so does the more modern 28nm based GTX670. It is not wrong to overprovision the psu a bit. It will only draw the wattage it needs.
I would suggest the PC Power and Cooling Silencer MK III 600W for $70 after rebate:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
7) Cases are a personal thing. Buy the NZXT if you love it. Otherwise, a perfectly functional case can be found at half the price.
The Antec 300 illusion model for $70 is very well reviewed:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
8) How much drive storage will you need? If you will store lots of video files, then a hard drive is appropriate, and the samsung 1tb is fine.
But, for your budget, I would try to incorporate a SSD into the build for the os and some apps.
A 120gb ssd will hold the os and a handful of games. It will not cost much more than a 1tb drive($105).
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Could you start with that, and add a hard drive latrer when you need the storage? Or, even a 60gb ssd will be enough to hold the os and a bit more for $60:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
9) As a first time builder, I suggest you download and read, now, cover to cover, the motherboard and case manuals.
Many questions will be answered.
-----------good luck-----------