bspwm, because it behaves and stays out of my way.
@fuuma I use Gnome because it works, and is a consistent experience (for me at least).
I would recommend it to beginners because its basic use is fairly ease to explain and demonstrate.
@fuuma KDE (personal devices) and Cinnamon (work).
KDE offers a familiar interface but doesn't compromise on options or flexibility, and it has a ton of well-integrated applications.
Cinnamon likewise because it has a familiar UI and everything "Just Works" on Mint with minimal need for tweaking.
The less time I need to spend adapting to an environment, the better off I am.
@fuuma Xuake. I use it because it's my Wayland compositor. It's a minimalist, cli-forward, lua scriptable anti-desktop. It's very lightweight and minimizes UX noise, probably to a fault for most people.
I love it becuse I wrote it to meet my exact needs. I haven't packaged it anywhere yet, so compiling and installing is an adventure.
@fuuma I'm a fan of MATE because I started with Unuuntu 10.10 and it's the most similar to GNOME 2.
I also like Cinnamon but for some reason it doesn't go to sleep when I close my laptop lid.