Ubuntu is my free Linux operating system of choice. There are many versions but this one has seemed to stand head and shoulders above the rest. If it's something you'd like to try out you can download it, burn the .ISO file to CD, and boot your computer entirely off the CD before you install anything. This allows you to take a trial run, and look around the basics of Ubuntu before installing it. With the popularity of Linux growing, alot of major manufacturers are now releasing their computers with this operating system installed. And why not? It's free, and includes many applications that Microsoft makes you pay extra for. They are always developing newer versions, so make sure to check out their website for the lastest version, and to make sure you download the one to best suit your needs.