My PC XP PRO SP2 (if I put XP after this, just figure it is PRO with SP2)
Wife's PC Windows XP 64-bit
Laptop Windows XP
Tablet Windows XP tablet edition
Sisters PC Windows XP
Server Windows Advanced Server 2000 (I should upgrade, but it is very stable)
Cluster : Ubuntu/beowulf (so Ubuntu X4 as there is a master and 3 nodes)
Backup server: Some flavor of linux designed for it (not by me)
Media server : ummmm...you guessed it Windows XP media center
Bedroom Media server : Windows XP Media Center (screw paying for a Tivo

)
Torrent computer (basically only runs azureus, scans the files, deletes virus files and then puts on the server based on first letter): Windows 2000 (just a 700mhz machine with low ram)
Work laptop: Windows XP
I think that is all of them //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif