openSUSE Tumbleweed, because it is the most stable and predictable rolling-release distro. When they update a package to a new version the do quite some automat

openSUSE Tumbleweed, because it is the most stable and predictable rolling-release distro. When they update a package to a new version the do quite some automated QA testing on it so it works properly, and also on the related dependencies so that all integration tests still pass before they release thw updated package to the repository. Also the snapper is very nicely integrated into the system, and before each updated a system snapshot is taken and also another snapshot is taken after the update. And the snapshots are automatically added to GRUB boot loader. So even if something goes wrong with the updated and th QA did not catch the problem you can still easily and quickly switch to an old working snapshot. In addition to this they also have one of the best KDE Plasma desktop integrations into the distro and their YaST graphical control/settings center is awesome.