I keep coming back to KDE time and time again. It’s so easy to mess with, I can set it up exactly how I like it without much effort, and it always looks good because someone else did all the work making themes and widgets I use.

That said, I love XFCE, I’m just trash with CSS so it takes me forever to get it how I like, and on my Surface I can’t get the scaling to work so everything is beyond tiny.

As others have mentioned, Debian stable and Xubuntu are my default recommendations for anyone who wants a simple “just works” kind of system. Debian if they want it to be as clean as possible, Xubuntu if they want some creature comfort right out of the box.