KDE, but only with an extension called kröhnkite for auto tiling. To me a manual stacked window management system is almost unusable. As someone who used tiling window managers for years and lots of KDE based applications, and as KDE was one of the first who worked well in Wayland, I thought to give it a shot. I like it and since then (years by now) stayed on KDE.
For reference, I used Gnome 2 on Ubuntu, made the switch to Unity desktop, then Gnome 3 (and I think Gnome 4 too?, don’t remember). Then started experimenting with Regolith, auto tiling for Gnome, and tried out real tiling window managers, until I landed on qtile. Then experimented with Xfce, before finally making the switch to KDE (because of Wayland). Rest is history.











Its different now, and I mean it. I used Krohnkite in Plasma 5 when it worked well, but later it started to be buggy. Its a fork from the original BTW and the main thing that is worked on at https://codeberg.org/anametologin/Krohnkite . I think reason it was buggy is, caused by Wayland or when transitioning to Plasma 6, forgot. Then I switched to Polonium (kwin script) and it worked but wasn’t great. But Polonium started to be buggy too,… then Krohnkite was reworked, even the Kwin developers made adjustments so that Krohnkite works well.
I am using it again since Plasma 6 launch period and it works well. Krohnkite is not buggy and it even got some cool features, where you can dock any window to the side or top or bottom side in a smaller area, that will not interfere with the other windows for tiling in example. So all in all, if you think about using it, then I can highly recommend Krohnkite.