I would say that the best os/distro is the one you’re comfortable with. With that said, I would really iron out why you want to switch, like what you’re looking for. Stability? Debian. Newest features asap? Arch. Mix? Fedora. General support? Probably any of them, but fedora or Debian if you want properly supported packages and not rely on the AUR. (You can use any of the derivatives, but I can’t say they do anything special for me, so I stick to the core distros)
I would say that the best os/distro is the one you’re comfortable with. With that said, I would really iron out why you want to switch, like what you’re looking for. Stability? Debian. Newest features asap? Arch. Mix? Fedora. General support? Probably any of them, but fedora or Debian if you want properly supported packages and not rely on the AUR. (You can use any of the derivatives, but I can’t say they do anything special for me, so I stick to the core distros)