Here's my situation, I'm still some what inexperienced in building PCs. Built my current one back in 2008 and really have only added a newer GPU (back then) and some RAM. I'm looking into getting into possibly overclocking but really just wanting to be able to upgrade my current build into a nice gaming rig.
Intel(R) Core(TM) i7 CPU 920 @ 2.67GHz
AMD Radeon HD 6850
11.5 GB of RAM maybe 1333 MHz don't remember
Corsair HX Professional Series 850-Watt 80 Plus
Mobo is a ASUS P6T (Has PCI 2.0 and supports up to DRR3)
Right now, I know I need to upgrade my GPU, looking at EVGA GeForce GTX770 SuperClocked. But what else is a priority asides my GPU? The i7 is ok I guess but the 2.67GHz doesn't seem like enough for some reason. Again still inexperienced so just looking for advice.
EDIT: BTW budget right now is roughly $500-$600, but not looking to spend it all on the GPU alone. I am upgrading my case as well to a Rosewill Gaming ATX Full Tower and if I get into OC then a Corsair Hydro Liquid CPU Cooler H100i as well.