Given your large budget atm, i'm a little surprised by the modest orientation of some of the parts in your system atm. Did you build the PC yourself on a budget ?
Anyway, as it is now, for that resolution your running, you'd easily be able to max out games with the [URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16814127685"]GTX 670[/URL] or [URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16814202008"]AMD 7970[/URL] (Check size of cards to your case dimensions). If your monitor is a regular TN panel, with these cards mentioned you could push slightly higher resolution, maybe consider a new monitor with a nice PLS panel screen e.g [URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16824236294"]ASUS PB278Q[/URL] or perhaps the same resolution you use atm just a better looking screen with IPS panel screen e.g [URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16824236288"]ASUS VS239H-P[/URL].
You'd need to replace the PSU with something more powerful. For just running a single card system the [URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16817182262"]Rosewill Capstone 550w[/URL] or more modest [URL="http://us.ncix.com/products/?sku=59615&vpn=P1550SXXB9&manufacture=XFX"]XFX 550w Pro[/URL]. Or if you might consider replacing the motherboard in future for SLI/CF then something like the [URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16817139010"]Corsair HX750w[/URL] or [URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16817207023"]XFX 750w XXX[/URL]. You won't need to CF/SLI on a single 1080p screen with these cards suggested.
And as Belimawr says, you could throw in a SSD. Or maybe put the system into a new, nicer case etc... improve peripherals etc...
Your biggest improvement atm would be a new GPU + PSU.
i5-760 2.8Ghz/Asus P7P55D-E / Titan Fenrir EVO/Kingston 4GB
2xWD C.Black 640GB (RAID 0)/Gainward GTX 670 Phantom/Corsair TX850w
Sound Blaster Z /CM 310/W7 HP 64bit/Asus PB278Q 2560x1440p
Zowie AM-GS/Filco Maj.2 (mx brown)/Senn.PC360/Corsair SP2500
Self built PC problems Here
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How to build a PC Here & Here