Question: I have decided to switch from Window to Linux.
Should I use Ubuntu or Kubuntu?
Or there are other handy alternatives?
I'm a LAMP based developer.
Any help would be appreciated.

Answer: 
It all boils down to personal preference. Since this is Linux after all, I'd suggest downloading and trying both out and sticking with whichever you're more comfortable with. Its the same underlying system but with a different "wrapper."

My personal preference is Gnome or [XFCE](http://www.xfce.org/about/). XFCE can be added to any version of Ubuntu or can be found in Xubuntu.
I think both have a live cd, try them out and figure out which one you like better. There are tons and tons of choices, which one works for you will be 100% up to you. Basically you are asking about gnome vs kde, which is a basically a religious war :)