macOS - because it just works and I like a clean, consistent ui.

I tried Windows, again and again - and it just feels like Microsoft is incapable of designing a ui that is consistent. Drives me crazy.

Linux, well. I like to run it on servers. I love it. But on the desktop it remains a pain. Yes, a lot has improved over the years. But there is still a long way to go before I would consider it user friendly. And the worst part: I do not see how a consistent ui would even be possible.