http://www.tuxmachines.org/node/33321  has been holding a poll on the late 2008 favorite distro. As one may guess, the Ubuntu family easily holds the lead in the poll, and has continued to do so at every juncture.
While I believe, on one hand, that every single one of the systems mentioned in the poll is excellent, I also believe that some of them are better at certain tasks than others. To me, the BSDs are great server systems. A few of them, such as PC-BSD and DesktopBSD have been created to make the desktop experience a bit easier to get into, but let's face it. BSD does servers really well. It can handle the desktop well, but that is mostly a function of what you put into it yourself.
Fedora, also being primarily the community and development arm of Red Hat, is also more focused on the server environment, though you can put together an excellent desktop with it.
For me, I really enjoy Debian based software. But plain Debian is also best suited for servers, even though you can make an excellent desktop from the software contained in Debian repositories.
So what makes a great desktop system right out of the box? Well, Ubuntu is popular for that, but the one that I really like is SimplyMEPIS. Why? It is really easy to install, and beyond that, it is extremely well designed, carefully engineered, with quality and usability in mind. What desktop user does not appreciate those traits in a desktop system? I assert that while many of these systems can do the desktop well, SimplyMEPIS does it cleaner and with higher quality than anyone else, and that is why I give it my vote and I've written this note to suggest that you take a look at it and see if you agree with me. The current release candidate, SimplyMEPIS 8.0 RC 1 should be released soon, but it is such a superior effort that the RC exceeds the desktop quality of most of the other alternatives, even now. Try it and test out my claim.