For a personal laptop: Fedora on a thinkpad (that’s what most of the core contributors use, which means the laptop drivers and tooling are always up to date).

For general servers: CentOS

For container servers: It’s not even close, Container Linux.

I think that depends on what you mean by "desirable design". Default appearance of the GUI, design of the packages and release schedule, choices in the filesystem structure, configuration in a default install?

For me it would be Fedora using Gnome

Elementary & Solus have been doing some very good work

Without systemd: Gentoo and Void Linux!