Stuff I care about
Promise I'm not just saying that. My time as a management consultant taught me how good designs should meet both business and user needs.
Quality of craft
I think good design is made in the details. It's one of the things I enjoy the most. All kinds of the minute details matter like box shadows, or error states.
Knowing how to code helps me speak their language and stay clear of the "computer says no" situations familiar to designers.