I have been using Apple Macintosh computers for a number of years. I used to own an aging Performa 5200 which was given to my parents. I then owned a Power Macintosh G3 - the beige desktop version. I would be extremely happy with a Power Macintosh G5. My main reason for upgrading was moving 6,000 miles away. I also wanted to run MacOS X - X being both the Roman numeral for 10, which is the current major version number, and a reference to its UNIX roots.
I actually have an iMac G4, but in reality, it belongs to my wife, Vicki. Its name is Gecko and it lives in our bedroom.
I would love to own a PowerBook or even an iBook. Of course, I wouldn't say no to an Xserve either. In fact, it would have pride of place in my dream rack.