I was a Gnome user for a few years till they started removing all features from apps under the disguise of simplicity. That's when I started with KDE for the first time and it was love at first sight.
I love KDE for many things:
- infinite levels of configuration
- sane, configurable keyboard shortcuts for everything
- very good, usable set of apps
- kmail, akregator, kwrite, kate, what not?