Many, from KDE/Gnome on Slackware to currently Linux Mint and Ubuntu.
The problem I have with the Linux desktop in general falls into three parts: The lack of consistency between the various desktops and the applications that interact with them, problems with drivers (when they work great, but when they don't you have to find a solution yourself) and sooner or later the updates fail in such a way that the only way to recover is to install the new version of the distro from scratch.
Windows is not free from flaws (it has several) but it is consistent, copy and paste for example always works the same way between all applications, and it maintains compatibility to the point where you can run applications from ten years ago without problems , this is really important when you have good applications that you use but that are no longer updated.
P.S: It's important to note that Microsoft is apparently doing its best to trash the advantages of compatibility and consistency after Windows 7, which is why I believe that I will eventually have to move to Linux if I still want a operating system for work instead of a toy.