For folks who like WinXP, PCLinuxOS "full monty" is a fairly close drop-in replacement.
Any KDE or LXDE desktop is functional enough, if not quite XP, but some are definitely closer than others. Run the "Live CD" version for a pretty good looksee.
Mint or Puppy aren't bad as simpler desktops.
If you actually like Win8/10, then you might like Gnome, and may God have mercy on your soul.
I've had zero luck getting Hackintosh/iATKOS to run, but count it as small loss since I can't stand MacOS anyway.
ReactOS is practically XP again but still too alpha for everyday use.