Corsair and Seasonic are two brands that have a reputation for high quality power supplies that consistently earn high marks in technical reviews. They are reliable, stable, and come with a 5 year warranty. Some of the newer models come with a 7 year warranty.
Currently I have a Seasonic X650 Gold that I purchased 8 months ago. I can confirm that it is an almost silent psu. It has a unique design which allows for passive cooling most of the time. Voltage has been well within specifications and rock steady.