Desktop environments should provide an unobtrusive base for other programs. You should not be fighting with it to get your work done.
I use the Mate desktop environment, which was created to continue the usability, accessibility and customizability features of the Gnome 2 … features that were unceremoniously removed and then presented as the new paradigm of desktop computing by the Gnome 3 project control freaks.
I also do not care for the other overhyped desktop environments, which endlessly and unashamedly imitate the Mac desktop, and project translucent chrome/backgrounds as the more-modern look. Oooh!
I extend my Mate desktop with my own shell scripts and Caja Actions Configurations (custom context-menu extensions).
I do not use the new desktop menu of the Mate desktop. There is an unhealthy competition between all desktop environments to reinvent and redesign the desktop menu. With each new version, you have to learn new ways of doing the old stuff. I do not suffer this madness. I remove the new menu from the desktop and add the Classic Gnome 2 menu in its place. I prefer functionality over flashiness. Microsoft Windows had almost perfected the desktop. Gnome 2 improved it by adding support for multiple workspaces. This made the evolution complete. It needs no further improvement. Desktop environments should just stay out of the way and let us work with more important applications.
KDE
I have known KDE as a solid desktop environment. I have not used it in over a decade. It was quite bloated the last time I used it. (Not slow. Just overdeveloped like a body builder.) Screenshots of the latest versions have not made me want to switch over. If you like KDE, you will do just fine with it. Unlike the condescending Gnome developers, KDE developers do not remove features and call it an improvement.