I have Unity, KDE (Kubuntu), and Gnome installed in 13.10. All three show up in the drop down when I go to switch users/login; KDE Plasma Workspace is the default option. I've tried lightdm, gdm, and kdm display managers. No matter what I do or how I select the desired desktop environment, my system always, always, always boots into Unity. (It did boot into KDE once and only once. After that I've never been able to get back into KDE.) I've tried everything that I could find in AskUbuntu except for some, like the ones that to tab to a nonexistent OK button in the drop down list of environments.
I've tried removing and reinstalling KDE. I've tried changing display managers. I've tried doing a full restart as opposed to switching users.
Does anyone have any idea how I can switch to a different desktop environment, other than Unity, without ditching my current installation totally and completely reinstalling Ubuntu?