Honestly, of the operating systems I've used over the years, none I've truly hated.
The two lowest ranking for me are Windows ME and 8. I can't speak to 11, I'm still on 10 and will be for a long time yet probably.
My favorites were DOS and Win 9x, with XP coming in close behind. Win 3.1 was nice, earlier versions, not so much. I just stuck to DOS.
Never played with OS/2.
I'm not a big fan of "modern" Apple environments, on both PC and mobile, but it's more about how Apples does things than the OS itself. I just prefer Android for mobile and I actually liked the classic Mac OS.
Have yet to find a Linux distro I dislike, but prefer Ubuntu.
Embedded OS.... only ever used one, Win CE, and it's wasn't all that bad.
Though, back in the 90's I worked with Ladder Logic a lot, but that's not an OS. It's a GPL used in PLC's. It wasn't hard, just annoying as heck. 😜