KDE works pretty well for me. The defaults are not bad, but it has lots of customization options. I mostly leave it on defaults, except for switching on focus follows mouse. You don't need to manually edit config files. It also has some nice (optional) animations. It's like a nicer Windows, with more customization and a more uniform UI (no mixture of historical UI elements).
Good grief, I wish I could agree. My experiences with KDE have been utterly horrible. Display scaling is flawed, the login screen keeps overlaying itself with a giant touch keyboard (I don't even have a touch device), my trash folder seems to end up read-only with alarming regularity, the application menu is twitchy and buggy, Konsole doesn't respect settings like unlimited scrollback properly, the System Settings is horribly laid out and crashes often (particularly when making network changes) and the people who designed KDE clearly have no concept whatsoever of whitespace (some menus are incredibly dense, other things like the application menu are huge with lots of wasted space). It feels like it was designed by programmers who know nothing about user experience.
The Pantheon desktop from elementary, on the other hand, is far closer to "sane defaults" in my mind and seems to be much less buggy.
