Ubuntu/Kubuntu/Xubuntu is based on Debian Linux. I prefer Debian, since it's users are typically more experienced, and the software is faster and more reliable. However, Debian is not as noob-friendly, so it has not had the influx of new users that Ubuntu has. But, I believe that Debian is technologically superior. So if non-graphical installers don't scare you, Debian "Etch" or "Sid" might be better for you.