It seems Linus likes KDE. I don't mind KDE myself, as that has been my standard Linux desktop for years (when I've been on Linux, and not OS X).
Right now I am trying out Gnome for the first time in a serious way, and to be honest, I like it.
I have used so many interfaces myself (Android, iOS, Windows 3.1/95/98/MIllenium/XP/7, OS X, Unix, etc) that I have come to the point that what I really care about is that I can get my work done.
The "cleanest" interfaces I have used have been the touch ones - iOS and Android. They are simple, but not exactly powerful, considering you only use one application at a time.
On Linux, what I care about is being able to launch Eclipse, Writer, Chromium, whatever. Give me a fast interface. Oh, and give me access to the command line. There are things that I can do better at the command line (Terminal Window) than using a GUI. Version control with tools such as Subversion is a good example. I also like quickly editing text files using vi. I know, I've just given Windows users nightmares ;) Oh well!