I've tried Vista on a laptop that is "Vista ready." It came with XP Media Centre on it.

It now has XP on it again.

Be careful retro fitting a computer with XP from Vista. Some of the new hardware won't work with XP.

Linux is a great way to go, if you can work with command line interface. The GUI (graphical user interface) in Ubuntu is great though. The only difficulty I see here is in finding the drivers that work well with the hardware. Most hardware manufacturers don't write the drivers for Linux, and sometimes it can be a real pain to find the drivers that will work with your chosen hardware.