Kbuntu vs Ubuntu... KDE vs Gnome... Which Desktop Environment Is Better?

I absolutely love linux. Over the years, I have always had an interest in using Linux. It wasn't until recently that I started using Linux full time. In the past I always had trouble either successfully installing the OS, or simply using it for day to day things. Today the story is much difference. Most of that can be credited to Ubuntu. It's an amazing operating system. But now I'm starting to wonder about the Linux Desktop Environment. Specifically, KDE vs GNOME.

If you have tried out both desktop environments (i.e. Kbuntu vs Ubuntu) let me know your thoughts between the two? Which desktop environment is better, and why? As you may know, Ubuntu uses Gnome by default, which automatically makes it more popular. That brings out a few questions, such as why Ubuntu chooses Gnome over KDE. Anyway, any opinions that you have about the two environments will be much appreciated.