Upgrading!

[droylock2]

Im trying to decide on what parts to upgrade first to improve my system. Its a bit out of date, but I want to slowly piece things together while seeing improvement. Here's my specs:
X6 1055t @3.5ghz
Antec Kuhler H2O 620
Asus M4A79XTD Evo Motherboard
Corsair Vengeance 8gb 1600mhz
HD 5850 1gb
Western Digital 500gb Hard Drive
BFG 1000w Power Supply
Storm Scout 2
Samsung 20" 60hz 1600x900 Monitor
Logitech mouse
Logitech G15 keyboard
Im not happy with a graphics anymore and is lacking. I would appreciate suggestions!

Edit: Since it was black friday today i went ahead and picked up a MSI gtx 670

 

[BreadWhistle]

If you are only looking to upgrade, I'd replace the CPU for a FX-8320 , get a SeaSonic X650

Or if you feel like dealing with re-installing windows 7, get a Vertex 4 128GB SDD , ASRock Z77 Extreme 4 motherboard and a i5 3570K

That would be mainly the best upgrade from your current system, though pricey.