I want things to "Just Work"
For the most part I run the installer (and users of certain other systems get to practice that quite a lot) and things do Just Work. What is really great is it then Just Continues To Work. Unlike some.
Although Bluetooth and WiFi are the worst faff I'd had the misfortune to endure in a very long time. What do most of the mundanes want? Right, most of them have never seen a network cable. Anyone working on the UI for those, please take a look around at the other OSs. Even if it's just Android. Biggest blocker as far as I can see.</rant>
Now I've said that, my personal desktops have been exclusively GNU/Linux since about 1997. It's almost always been capable of what I want from it, and it just keeps getting better. Anyone who has contributed to that, have my thanks and a few of the icon.