I prefer KDE, but I use a variety for all of my VMs and such. For my main stuff I use KDE, but I do have Xfce on a few things other than Pandora. GNOME seems a popular default for most of the distros I have been working with for the last couple months.
I look forward to having the option to choose between KDE, Xfce and CDE. My current plan is to use KDE when I am doing productive stuff with the desktop. Maybe I can use CDE for retrogaming and such. I know, this will be a silly way to do things.