As someone who can't stand a loud PC, I'm always on the lookout for new, high-performing yet silent cooling products. So far my favorite has got to be Zalman's Reserator 1 Plus, but there are lots of choices out there. Like the Evercool Silver Knight reviewed at ThinkComputers.org.
"Liquid cooling is becoming more and more mainstream, but most liquid cooling solutions involve lots of parts and lots of time to assemble. Evercool may have the solution to this problem with an interesting looking product they call the Silver Knight. It is a CPU cooler heatpipe cooling solution with built in water cooling. The Silver Knight is something that might interest a lot of people, I've had it installed for a week now and I am VERY impressed with the results I am getting from it. I believe Evercool has got a winner here for those looking for the advantages of liquid cooling but not all the hassles. Let's check it out."