I've long been a KDE user, switched to it in the KDE 4.1 days and never understood why people were so unhappy about it. I found it to be slick and useful, despite the regular problems with the NetworkManager applet in Debian Unstable. I just used the Gnome applet instead, which fit without a hitch.
Last year, finally frustrated enough with juggling between the windows of my various terminals and editors, I chose to give a tiling window manager a good try, and spent some effort on the ill-named Awesome (seriously, how do you SEO that?).
Though it's certainly not aimed at Joe Six-Pack in that you actually have to edit the Lua-based config file to configure it yourself, I found it extremely powerful and perfectly suited to my needs. The "tag" system to organize your window is supreme in allowing me precise control over which windows to display.
I discovered that I didn't have a use for all the frills of Gnome and KDE, except for USB-key and Wifi network management which are both accessible from the CLI anyhow (see udisks and nmcli). ... does this mean I've turned into a greybeard?