Corsair AX850 850W
 

Corsair's AX850 is an 80Plus Gold certified 850 watt power supply that aims to be the highest-quality model in its segment. It is fully modular and shows excellent performance characteristics in our demanding test suite. With a price of $180 it is not cheap but quality has its price.

http://www.techpowerup.com/reviews/Corsair/AX850/