From best to worst
1.Burning Crusade
2.Mist of Pandaria
3.Wrath of the lich king
4.Classic
5.Cataclysm
6.Warlords of Draenor
7.Legion
Legion is just the worst thing ever made. Makes Diablo 3 look good. And i guess that was the intent?
Plus with Ion at the helm what could go wrong?