Let's see... I have an AMD 64bit desktop I built for for editing video. It uses XP.
I have the old AMD I built for editing video running Win2K pro. It is retired, and used for mostly Duke Nukem and surfing and graphic design.
I also have an IBM Thinkpad with a blown ethernet. It also runs 2kPro, mostly used for playing CDs when I'm away from the PC, because I can't get it online.
A Gateway laptop with dead screen, used to collect dust samples these days, also on 2K Pro.
I built my wife's AMD, also running 2K Pro.
I got my boys an old iMac G3 Blueberry, running OS X. I bought this because it was really cheap, and is just like one of the Macs I learned Graphics on.
If I can ever get a new screen for the Gateway, I am pretty set on turning it into a Steam Punk laptop.