Since Kubuntu went completely into the hands of the community, has not stopped growing. Kubuntu 12.04 LTS and Kubuntu 12.10 are really excellent, fantastic !!!!
And, how could it be otherwise, Kubuntu 13.04 is really great too, as people of Kubuntu is really doing very well, the truth that I'm hoping with affection the next Kubuntu LTS to see how they have left (Kubuntu 14.04). To my view there that no hitting than Kubuntu and Linux Mint KDE.-
Linux Mint 17.1 Cinnamon
Linux Mint 17.1 KDE
Manjaro Linux KDE
Manjaro Linux XFCE