Check out the following article : Ubuntu Linux vs Windows Vista: The Desktop Battle
It may be a brave opinion but I predict that Ubuntu Linux and Windows Vista are going to be the two operating systems that will take over the largest chunk of the desktop OS market during the next couple of years. This comparison is based on my experience with both systems during the last couple of weeks on two different computers. Borys Musielak
As you can see both systems have their glitches but in the end both should work for you, as long you don’t try to “fix” too many things on your own. It’s always good to have a computer guru available as your first aid with the OS, especially at the beginning. Finally, in both cases make sure your hardware is supported. Both OSes are pretty new so not all the hardware (especially exotic WiFi adapters, TV cards and so) is supported, yet. If you don’t know how to check that, just buy a computer with operating system preinstalled. It’s easy these days to buy either a Vista or Ubuntu laptop or Desktop. Dell supports both of them, as one possible choice.