Desktop environments are a very personal thing in Linux, and there are many to choose from for each user. KDE, XFCE, GNOME, Unity, and many other options are available in various distributions. Each desktop has its pluses and minuses, with some being more traditional and others being more modern. But is there one that towers over the others? Well, Datamation thinks that if there is one then it's XFCE.
According to Datamation:
XFCE keeps it simple. XFCE remains rock solid, dependable and maintains the logic that most people still look for in a menu driven experience. I also happen to think that XFCE provides a solid balance between desktop environment speed and general usability.
The point is this – park any basic Windows users in front of XFCE and in minutes, they'll find their way around. I don't have the same confidence with GNOME and KDE in this area. GNOME 3 is completely foreign to most people whereas KDE starts off familiar, only to offer menus on top of menus which may overwhelm some newer users (my opinion).More at Datamation
Uh oh, I hesitate to offer my opinion about this because I'm rather hopelessly biased when it comes to XFCE. It's always ranked right at the top of the charts in terms of Linux desktop environments for me. It just seems to meld with my workflow much better than KDE, GNOME or most other desktops.
When someone new to Linux asks me about which desktop to use, I share my preferences with them. But then I usually recommend that they try a number of different desktops before settling on one. You can't really know which one you like best if you don't have exposure to a number of different desktop environments in Linux.
It's somewhat dangerous though to proclaim that one desktop environment is better than the rest for the simple reason that we are all different. XFCE might work beautifully for me, but you might loathe it if you are used to another desktop. So it's completely subjective to say one desktop is "better" than all the others.
Thankfully we are blessed with so many different desktop choices in Linux that nobody is stuck using a desktop that they don't like. Remember when Ubuntu switched to Unity? Some Ubuntu users couldn't stand it so they decamped to Linux Mint or other distros. The ability to make these kinds of choices is one of the things that sets Linux apart from Windows and OS X.
So when you get right down to it, the best Linux desktop is simply the one that you prefer to use each day.