Ubuntu, OpenSUSE and Linux Mint are three of the top Linux distributions, according the Tech Radar. Debian and Elementary OS are also popular for Linux users. More experienced users, however, might prefer Gentoo or Arch Linux.
As noted by Tech Radar, choosing which Linux distribution to use is highly dependant on a user's personal needs and level of experience. Ubuntu and Linux Mint are very flexible distributions capable of being enjoyed by both novice and experience Linux users. Debian is more specialized for users wishing to run a server. Arch Linux and Gentoo are more useful for highly experienced users, who are looking for fully customizable systems.