Since Cataclysm, it seems every odd expansion has been bad, and the ones immediate before or after have been considered very good.
Wrath (good) -> Cataclysm (bad) -> Pandaria (good) -> WoD (bad) -> Legion (good) -> BfA (bad) -> ??? (good)
I suppose the reason for this could be them pumping out expansions much faster than before. Maybe the better ideas just take longer to work on. So I'm wondering, what would make the next expansion great for you? What made the previous ones good for you? I personally loved Cataclysm, but I'm a huge fan of dragon lore.
I'm looking for something to be monumental in the next expansion... like a 3rd faction being added.