@1ce4e61d
ChromeOS.
It's Linux.
I'm not a fan of Google, but let's not get into the evil Google stuff. It's your most likely choice if you want to get someone off of Windows and not be their personal tech support team. A good number probably use Chrome and Google services (on Windows) at this point anyway. 

 @dd0abf19 I do count Chromebooks as Linux, but that's not the Linux I would like to recommend, as much as I secretly love and own a Chromebook.