For a purely gaming rig, you don't need an i7 or $2400. You can get a killer system for a grand less.
Also we need more information, can you fill out this form. It will mean we arent flying blind to what you need and want.
http://www.tomshardware.com/forum/353572-31-build-upgra...
But heres my crack at it from I know so far.
CPU: i5-3570k. $230
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
For gaming, an i5 is all you need. Its a waste to get an i7 as its hyperthreading technology just isn't utilized in games.
Motherboard: AsRock Z77 Extreme4. $135
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Very good motherboard, have it personally and nothing but praise. Heres some reviews of it.
http://www.vortez.net/articles_pages/asrock_z77_extreme...
http://www.tomshardware.com/reviews/z77-express-ivy-bri... (it tied first for mobo's under $160)
RAM: G.Skill Ares 8GB (2x4GB) 1600mhz CL9 1.5v. $44
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Fairly standard kit of low profile RAM
PSU: Corsair HX750, semi-modular, 80+ Silver. $145
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Good brand, modular where it needs to be, fairly good efficiency. Can upgrade to Gold efficiency through some Newegg deal, not sure how to do that though.
GPU: Gigabyte GTX670. $400
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
If multiple monitor gaming is a possibility, you should consider the HD7970. But on a single screen, this will do just fine.
Gigabyte, ASUS, MSI, Sapphire, Zotac are all good manufacturers to pick from. I avoid EVGA because they use a reference design on their cooling.
HDD: Seagate Barracuda 1TB 7200RPM. $90
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Fast and inexpensive compared to Caviar Blacks,come with less warranty, but a HDD will fail within three months or never. Get more/bigger drives if you need the storage.
SSD: OCZ Vertex 4 128GB. $115
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Trading blows with others for the fastest SSD on the market, and if OCZ keep pumping out updates, will only get faster.
CPU Cooler: Coolermaster Hyper 212 EVO. $36
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
The go to budget air cooler. Will easily support moderate overclocks on the 3570k.
Case choice is largely personal, you have to like the look of it after all. Here are some good choices, but feel free to find your own. Just make sure to research it first though.
Coolermaster HAF-XM. $130
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Its a "mid-tower" that's only a few inches smaller than a full tower. Plenty of space and amazing features (My personal choice).
Corsair 400R. $140
Subdued aesthetic, great features. Wont find much wrong with the case.
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
NZXT Phantom, various colours. $120
Also a good choice.
http://www.newegg.com/Product/ProductList.aspx?Submit=E...
Total: $1335 (Corsair Case picked)
That rig can overclock and has the potential for dual graphics cards. It will play the latest games at max settings.