It is coming on 15 years since the original announcement for KDE. For most of my time using Linux KDE has been my preferred desktop environment and still is today.
The first time I saw KDE was in about 1998/9 when I installed Mandrake on my aging Windows PC. It took a few years before KDE/Linux became my default environment and then I did head to Gnome land around KDE4/4.1. But that is history.
Today I run Kubuntu not only for personal use but also business and software development. By the weekend it will be Kubuntu 11.10 with KDE 4.7.2.
And should I go down the tablet route, KDE might have me covered with Plasma Active.