Noctua NH-U12F CPU Cooler
 

Noctua's NH-U12F CPU cooler is a high-performance heatsink that uses eight heatpipes to get the heat off your processor. The included fan is of the 120 mm variant and is fairly quiet. If you need to reduce the fan noise even more you can use the included Ultra Low Noise Adapter which makes the fan almost inaudible.

http://www.techpowerup.com/reviews/Noctua/NH-U12F