This is probably subjective. Many people hate Ubuntu based distros for various reasons. If you're a beginner you'll hate Kali or Arch Linux. Red Star is probably bad 😂 That's the North Korean distro. All of my servers from the late 90s and early 00s were Slackware. I'd probably not recommend that now as it seems not as popular. 

 I used freebsd in the 90s and early 2000s. still think bsd is better than linux :-D 

 Ubuntu for example with their canonical stuff they are crossing some borders. Instead of Ubuntu I would go with Debian. There are some others with telemetry which means data collection.
In general I would be prefer the "root" versions and not the "forks". 

Arch
Fedora (telemetry check)
Debian