Arch Linux. Always very up-to-date and the AUR is huge. No dealing with PPAs or snaps or flatpaks or appimages. Just paru -S any-software-ever-made. Also very streamlined (systemd for everything lol) and well documented. I tried NixOS for a bit but it was very inconvenient in comparison and I felt like it was impossible to tinker with or understand if you weren’t good at Haskell. Terrible documentation.