I just bought my third GTX 470 last night, and I will need a bigger PSU. Right now I'm running 2 on an Antec Earthwatts 650, and was looking at PSUs in the $100-150 range.
I know that the Corsair HX 850 will work, but it's a tad bit more expensive than other PSUs, such as the Antec TPQ-1000W...