NZXT Respire T40 Heatsink
 

If you are looking for good cooling performance without a bunch of noise, the gang at FrostyTech recommend the NZXT Respire T40 heatpipe HSF. At the heart of this 158mm tall heatsink are four 8mm diameter copper heatpipes and a 120mm, 68CFM fan. The heatpipes are all exposed at the base while the aluminum fin stack is pretty standard; there aren't any fancy leading edges, punched out cooling fin patterns or unnecessary plastic fan shrouds.

http://www.hardocp.com/news/2013/01/..._t40_heatsink/