Ubuntu is getting pretty popular lately but I thought it would be a good idea to post some info.
Ubuntu Linux is a desktop linux based on Debian. I tried it 2 months ago and it has become, along with SuSE, my favourite Linux distro. Right now its the OS I use 90% of the time!
To all Linux newbies out there, this is a user-friendly distro. Installation is fast and easy, and install new software is easy thanks to Synaptic (GUI for Debian's apt-get). I found all kind of stuff in the database, including nVidia and ATI drivers for easy install of 3D acceleration. Videos and music play fine.
Note that the windows manager that comes with Ubuntu is Gnome. Some may not like that (as KDE is more powerful and "pretty"), but there is a project called Kubuntu that allows you to setup KDE by downloading all the files.
You can download the ISO at http://www.ubuntulinux.org/
There is a nice and active forum at http://www.ubuntuforums.org/
And of course I am waiting for your comments after you've tried this! Feel free to ask any questions etc.