TBC.
I hate Outland. I hate Draenei (who weren't anything like what they should have been if they had actually stuck to their own lore). I hate high elves for the horde (screw you China!). I hated the dungeons, the raids. I even hated Illidan and I LIKED him in Warcraft 3.
Tbc was full of utter crap and imo the only reason it's liked so much is because people were still on a vanilla high back then. It was an unacceptably bad expansion.
As for the probable 'winner' of this thread; WoD just had a severe lack of content/updates. But what was there, was miles ahead of anything in TBC.