Windows 10 for desktops/laptops/tablets/phone. FreeBSD for servers.
I love Visual Studio, especially C#. I love the UI. I hate the updates, but I can kindof live with it. The MS account support for Windows 8+ is awesome when using multiple computers and devices. I actually use and enjoy some of the store apps. For FreeBSD, it's the ports system. Being able to build from source with compile time customization yet full dependency resolution and update support, that also integrates with the default package manager is really awesome.
One thing I really don't get is why the whole Ubuntu on Windows is such a hyped feature? I've been using Cygwin for 10 years or so now, which has pretty much all of the tools and stuff from the OSS world, so what is so much better with running native Ubuntu binaries? Can the native Ubuntu binaries even interact with native Windows binaries (for example, piping output to eachother etc)? I'm guessing I'm missing something big..?