Raistline on 19 April 2017
You forgot to add Windows 8.1 as it is vastly different and superior to Windows 8. Also, Ubuntu is Linux.
My answer is quite a bit more complex than just a favorite OS as it all depends on purpose.
Favorite OS for home Server: Linux Mint (latest stable.)
Favorites OS for games and productivity: Windows 10 (Windows 8.1 coming in a close second once the Start screen is removed.)
Favorite Server OS for Directory Services: Server 2012 R2 (Server 2016 is not mature enough.)
Favorite Server OS for non-Directory Services usage: Linux CentOS/Redhat.
