XFX GX260XAHBF Black Edition GeForce GTX 260

Requirement; PCIE slot and two 6 pin connectors
Manufacturer's Minimum PSU Recommendation; 500 watts / 36 amps ( varies slightly from man. to man. )
Actual power consumption of a GTX260; around 105-150 watts depending on the card and OC
http://www.xbitlabs.com/misc/picture/?src=/images/video/evga-geforce-gtx260-216-55nm/results/evga260_power_full.png&1=1

I have no problems running an overclocked original ( 192 core / 65nm ) on an Antec EA430 ( E8400@ 3.6 / 2 x 160 WD Raid0 / 2x2 DDR2 / DVDRW / sound card and GTX260 ), not that I'd reccomend it to anyone.
Kind of hard to recommend a psu for you without knowing the rest of your computer specs, but a good quality 500 watt unit is enough for most systems.
 
I have a problem with the size of the power supply, the size that is compatible with my case is 5.9" x 5.5"x 3.4", that's why I choose that power supply for that video card.