Windows 10 and Ubuntu 16.
However in most cases it does not matter any more as @davidfekke said. Whatever is the best for you.
When I do some Ruby I use Ubuntu with RubyMine. When I am writing C# I go to the Windows because I still prefer Visual Studio even though I am starting to use more and more .Net Core. Also Jetbrains are working on Rider which is an awesome C# IDE on top of their platform which will work on all OS.
So in the end of the day it comes to personal preferences and what suits you best. Obviously if you are doing some Mac Os, iOS development you would go with a Mac.
And on the note of the hateful comments - ignore them. The internet is full of this kind of stuff.
We have a lot of choices how and with what to work and that is an awesome thing! :)