I recommend Manjaro to every windows user wanting to use GNU/Linux because it
is a 'gamer' distro so many non-free games,non-free GPU Drivers, and non-free
applications are available. It is rolling release, which is more similar to
what windows has where applications just decide to f---ing update whenever
they please. It is easier to install then Arch, who in the right mind would
recommend Arch to a windows user?
Feel free to replace 'windows' with 'mac' above
Though Ubuntu would be also be a great non-free alternative. There's a huge
amounts of online Q and A's regarding Ubuntu. It's also really easy for a
user to figure how to install what they need.