Linux Distributions for Professionals
If you currently work in IT or aspire to work in IT, then use RedHat, CentOS, or Ubuntu.
Linux Distributions for Hobbyists
If you are using Linux as a hobby or for personal projects, then almost any Linux distro will work. Stick to the most popular distros as you will be better supported if you need help.
Here is the list of the top 10 most popular Linux distributions:
For even more Linux distros to choose from, visit DistroWatch.
The Biggest Distro Mistake Beginners Make
If you are new to Linux or a looking for a general purpose desktop distro, do NOT use Kali Linux.
Kali is a very specialized Linux distribution. It doesn’t work like ANY of the other distros listed above. If you are ONLY interested in penetration testing, then Kali is for you.