Which one is better? Ubuntu or Kubuntu
 

Which one is better? Ubuntu or Kubuntu.
Specially for people used to Windows.

If you are totally new to Linux, they'll both be very different from what you've been using so far(Windows). Maybe you can try live CDs of both Ubuntu and Kubuntu before deciding.

I think Ubuntu is more friendly with windows user

Optically, Kubuntu is more like the Windows environment and Ubuntu tends slightly more towards the Mac interface. However, you can always run, say, ubuntu and install all KDE packages (which I do - I like the KDE software, but I don't like to interface).

But don't get fooled - as my predecessor said: they are different from what you are used to. It takes a while, but it is well worth the effort!

Well that's easy, Debian :D

Think! Both exist both are used by lots of people. Why would your first question on a forum like this suggest that one is "better." Are you trying to start a flame fest? Are you some kind of troll? Or, Are you some kind of a straw man (ref: The Wizard of Oz.)?

Both Ubuntu and Kubuntu are identical Linux operating systems based on the Debian base. The difference between the two is the GUI desktop used. It boils down to a matter of preference. Try both and see which one you prefer. Better is a subjective call when it comes to the differences between these distributions. Someone may say one is better but if you try them you may prefer the other.

I think you spelt Slackware wrong. ;)

I personally like Kubuntu. I haven't tried Ubuntu but the reason I chose Kubuntu than Ubuntu is that Kubuntu is blue and thats my favorite color. You will get mixed answers here cause each person like a different thing. I would say try them both, use kubuntu for a full day or 2 and then try ubuntu for a day or 2 and then decide.

kbuntu is ubuntu with the kde desktop.

my advice is to insall ubuntu then using synaptic install the kubuntu-desktop pakage,

this will give you both.... you can then coose which enviroment you want when you log in