I’ve been a big fan of Ubuntu since I decided to switch one of my machines to Linux—I went through a lot of distributions, but Kubuntu was the only one that stuck.
I’ve had some problems recently with the normally excellent Synaptic on Kubuntu recently, but otherwise it’s a great linux distribution.
So it’s no surprise that Google Trends ranks Ubuntu as this year’s top linux distribution.
Fedora , SUSE, Ubuntu, Debian, Gentoo

I feel like out of all the linux distributions, only the Ubuntu project is really getting it right for a mainstream linux distro. They have a great and understandable philosophy, their distro ‘just works’, their security setup is smart, generally I haven’t seen any area in which they are getting things fundamentally wrong.