For a while I've been wanting to make the server in my office go quiet. This server is my workhorse for my home office and it's critical it's always on. Not only is it the DC for my home domain, but it also coordinates all backups and runs VMWare Server for hosting a few development and production virtual machines. The box doesn't have a lot of noise generating components... no video card (just using the onboard video) and a few 3.5" drives (five to be specific). The fan is the stock one that AMD included with the dual core x64 CPU. The problem is the case wasn't configured for noise reduction and just seemed loud.
After reading Scott's experience building a powerful box, what really interested me were Scott's and Jeff's comments about the case they used: Antec P182 Gun Metal mid ATX tower. Scott's comments on how quiet it was resonated with me so I decided to order one. Just finished moving all the parts over to the new case and I have to say, I'm BLOWN AWAY how quiet this case is... absolutely blown away.
The subtle design facets of this case are quite impressive. It's got three huge, yet silent, fans that all have 3-configurable speeds. The motherboard tray is elevated about 1cm so you can run cables behind it (nice for the two fans at the top). There's absolutely no opportunities for bare metal-on-metal contact. What's really cool is how the drives are mounted. The 5.25" drives slide in on hard rubber rails. The 3.5" drives are literally suspended in silicon! What you do is put the drive on the silicon cylinder and screw the drive in using this longer screw that goes through the cylinder... this attaches the drive firmly, but the ONLY thing the drive touches is silicon... genius! You can kinda see the silicon cylinders in one of the bays on the Newegg picture... look at the middle bay, the four white things. The 3.5" drive bays are also removable and slide in/out on hard rubber rails... very slick. Took a few pictures but they came out looking like crap. Adding a few new drives and new PSU in a few weeks so I didn't take too much time organizing cables or adding egg crate foam (but I did add the PAX.mate to both sides to help dampen it a bit.)
This machine is now literally quieter than my laptop! I've already hit some of the SharePoint sites I have running in virtual machines on that server to make sure it's on... damn thing is amazingly quiet! The A/C duct above my desk makes more noise.
If you're looking to go quiet, go P182. Yes, it's pricy ($150), but it's awesome.