My favourite DE has got to be Cinnamon, as much as I like KDE and XFCE, I prefer the simplicity of cinnamon where as in KDE has a bit too much of everything in the customization scene and XFCE I find a little tricky to get tiling working right.
Cinnamon to me is perfect as I easily transferred from Win 10 to Mint and soon Manjaro Cinnamon Edition.
What is your favourite DE and why? Tiling WM DE's can be counted as well seeing as they have nifty navigation features.
I use kde6+Wayland. I do like the simplicity of Cinnamon, but it runs games slower than kde, even though mangohud claims they run at the same speed. For example, in Cinnamon it'll say 60fps when it's clearly in the 30s-40s, and kde actually runs the same thing at 60fps. This is with every tweak i could find, and yes, including turning on the setting to turn off compositing during games.
Kde6 is still quite buggy at times, but I'm really enjoying Wayland's smoother general behavior over x11, even with x11 stuff like wine/proton. This is on arch + AMD rx 6600 xt. I used old gnome 2, then mate, then Cinnamon for years, but if KDE can clean itself up a little bit (no judgment tho, i get it) it may be my permanent DE. Generally when i go to report a bug, it's already reported by someone else...