Heh... I'm in a similar boat. I built my own machine with the big old Antec 1030b. I unhooked the two extra fans and it turned out the fan on the video card was going bad... replaced that and the now the hard drive sounds like a phaser on overload.

Well I decided to get a brand new Seagate Barracuda on the recommendation of a friend. I'm installing it this weekend... it's supposed to be completely silent.

On a somewhat related note, audibly I cant even tell this new Dell here at work is even on… It’s creepy.