Ultra LSX 750W Power Supply
 

I know from past experience that other Ultra power supplies haven't quite been up there with the best, but the LSX 750W electrical performance is excellent. The DC voltage load regulation, in combination with very low noise/ripple levels, make for very good DC quality on all the rails. The efficiency, though not quite meeting its 80 Plus Bronze certification following the OCC power supply testing methodology, is still very good at 87% maximum.

http://www.overclockersclub.com/reviews/ultra_lsx_750w/