Windows since 3.1 (though I was never an every day user of Vista and 7), OS X pre-Lion, GNOME 2, KDE 3.
OS X has a better combination of desktop quality and application support, but if Unity could magically run OS X apps, I don't think I'd ever use or recommend anything else.
OS X has a better combination of desktop quality and application support, but if Unity could magically run OS X apps, I don't think I'd ever use or recommend anything else.