The five most popular Linux distributions are Ubuntu, Debian, Fedora, openSUSE and Arch Linux. Each distribution has a different focus on what experience it should deliver to the user. There is no definitive answer for which distribution is best, as each individual must decide what is important for himself.
Each distribution, or distro, comes with different desktop environments and software included. The most common choice for users new to Linux is Ubuntu. There are many alternate versions of Ubuntu such as Kubuntu, Linux Mint and Elementary OS.
Zorin OS is designed specifically for users unfamiliar with Linux. Arch Linux is at the other end of the spectrum, focusing on customization and minimalism, but requiring much greater familiarity with Unix-based operating systems.