Scythe SAMURAI Z Dual Heatpipe CPU Cooler
 

The Scythe Samurai Z cooler turned out to be an exceptional improvement over the stock CPU cooler included with my P4, and a great addition to my overclocked system. The cooler itself does the job efficiently and relatively quietly - I can hear my GPU fan and the flow of a good collective number of CFMs, but no annoying whining or whirring.