I bought this the last time it went on sale and am happy with it. It is not whisper silent but definitely not noisy whatsoever. It reduced the idle temperature of my Sandy-Bridge i7 2600K processor with stock Intel heatsick from about 60 degrees to about 35 degrees. Very happy with the purchase and highly recommend.
$9.99 after $10 MIR. Free shipping.
"The ZALMAN CNPS5X Performa is a quiet, yet powerful CPU cooler on a budget. An ultra quiet 92mm PWM fan with fluid shield bearing, three heatpipes and aluminum fins combine to deliver efficient heat dissipation to keep your CPU cool. Broad socket compatibility makes it suitable for almost all the mainstream motherboard platforms."