It's not cheap but if you're looking for a high-performance cooler that
delivers excellent performance at low noise levels you may consider this HSF.
"Today we test the most high-end heatsink from Noctua. It comes with two fans pre-equipped and will fill up all but the largest eATX cases. Dubbed the NH-D14 this beast comes with a 120mm AND 140mm fan which are spec'ed for low noise operation. Can it handle the heat of an overclocked Core i7? Time to find out."