I've installed Ubuntu, a Debian-derived desktop Linux distribution, onto Clarence and Leroy, my two workstations. Clarence and my laptop Niamh (running FreeBSD) tag-team as my work machines, while Leroy is for kirinqueen, so she has a computer to use at my house:

kirinqueen using Leroy, with Niamh and Clarence to the left

So far, my Ubuntu experience has been entirely nice. The install is particularly painless.