The Apple Xserve also looks really nice for server gear but is just added expense. This is because most of the time the servers will be sitting in a rack somewhere and I don't really need to stare at the front too much.

Trust me. There are people who care about how their servers look. I had a rather upset customer over the fact that the DLT drive mounted in the server didn't line up flush with the front face, due to a mismeasurement of where the screw holes were placed on the server.

Oh, and just to add to the Panther comments. Fast User Switching, done right. It's rather nice, and I personally use it to switch to my "Work" desktop when at work, or back to my "Home" one at work. Unlike Windows XP, OS X dosen't disable this feature if you are part of a domain. And I have domains at home and work, so I have never used XP Fast User Switching.