NixOS. I’ve been running Linux since Slackware 1.0, since then have run Debian, LFS, RedHat, CentOS, Gentoo, Arch and Ubuntu. After years of Ubuntu I discovered NixOS and after diving deep into it, have never been happier with a distro. All of my machines and dot files are in a straightforward single language in a git repo. The mutable parts of all my applications are nicely isolated and backed up and I can make changes to my systems fearlessly. It has a very steep learning curve, but it’s amazing.