For me it’s PeppermintOS.
I started my Linux adventure a few years ago, and haven’t owned a Windows PC since.
I currently use Arch on my main rig, and I wanted to install Linux on two old laptops that I found laying around in my house
I then remembered the first distro I ever used, which is PeppermintOS, and I was amazed at the latest updates they released.
They even have a mini ISO now to do a net-install with no bloat, with a Debian or Devuan base.
Sadly, I believe the founder passed away a few years ago, which is why I was really happy to see the continuation of this amazing project.
NixOS has the worst documentation I’ve come across. It’s difficult to describe just how useless it is despite its wealth. It’s neither a manual, nor a reference, nor a guide, but all three jumbled in one and that goes for the package manage with its DSL, the operating system built on top of the package manager, and the tooling.
The best description I can think of the documentation of that project is “everything is everywhere”. Bless their documentation team volunteers that are trying to figure out the absolute mess it is. They have my utmost respect.