Mists of Pandaria by far. That sha thing and ninja stuff is pure garbage and doesn’t belong in Warcraft universe.
Cataclysm could have been played out a lot better. Deathwing fight was a nail in the coffin. Everyone expected s least an epic battle with a corrupted Aspect of Earth, and ended up killing tentacles for 2 fights. The huge dragon was a bunch of tentacles, no joke.