Working on Precision 390s today. This is a nice Dell desktop, capable of taking up to four SATA hard drives, with options for RAID, and a single core Intel or Core 2 Duo or Extreme or Core 2 Quad Q6600 CPU.  There's three PCI slots, and three PCI-E slots, including one for a video card. If you want faster hard drive speed, you can put a SAS-5i or SAS-5ir.

I used one of these machines myself, and I loved it. One thing I particularly liked about it is how quiet it is. I have two set up in the tech room right now, and if I stand next to one, I have trouble hearing it over the sound of a server running that's over ten feet away. Makes for a nice system to have at home or in an office where you need a quiet computer.