What Operating System do you use?

Win 10 64 - its fast and it works.
I put Linux mint on my laptop, not bad.
I also have virtualbox on my win 10 , with a number of different Linux guests.

Mac Pro at work and MacBook Pro at home,
antiX Linux for my crappy netbook and Windows 7 for my 2009 gaming desktop

I've gone through many operating systems till this day.
Got MacOS working on an old Asus notebook and in a virtual machine. Since Ubuntu 07.10 i was desperate dual booting. Fumbled with Debian/Mint/Zorin/etc. Gut stuck with Manjaro in the end.
Was using Manjaro on my main Desktop for half a year without dual booting windows. But going more into gaming with the newest titles from torrents was not an easy task so i moved back to Windows 10. Got Windows mainly slim, without Apps, Telemetrie and all other bulls***.
Still using Manjaro on my Lenovo notebook and can't think of any other Operating Systems for my home and internet server than Debian.

Good old Windows 7. Never liked macs, never wanted the hassle of Linux.

Windows 10 now kind of a must especially with the new games coming out

Still on Win7

I used Windows since my childhood, the earliest I remember (other than DOS and Norton Commander :)) is 3.11. I've used all of the consumer versions since then. Now I had a chance to try Mac OS X since a couple of months - I like it much more and I hope I can use only this OS from now on! :)

I currently use:
1. Windows 10: Work and Gaming
2. MacOS: Macbook Air
3. Linux (Ubuntu): Desktop

Windows 7

Win 7