I have two PCs that cannot be upgraded beyond XP for hardware reasons. They work great, but some vendors say their programs will not run on an unsupported operating system. I have a couple other machines that are still on XP for compatibility with the first two.
One newer machine came with Win 7, but it wants to use Home Group networking, which is not compatible with the rest of the world, and struggles with standard networking (Microsoft arrogance trying to force their master plan). We live with standard networking that Microsoft tries to avoid.
Another machine is on Windows 8.1. I tried to upgrade to Win 10 but it would not support some of my older hardware such as printers and scanners (drivers not available for Win 10) so I went back to 8.1. 8.1 also wants to be on Home Group networking, but seems to support standard networking better. You must organize your data in the Microsoft assumed directory structure - not bad, but not what I would choose - I find it confusing, but my son says the confusion is just because I am getting old.
Since I am an old fart, I will conclude that my preference is for Win XP - but it doesn't support the touch screen on my Windows Surface Tablet.