I’m bad with directions. People mount up and disappear. I spend most of the dungeon trying to find the group. Then there’s that hill people like to fly to in the no-fly zone so you have to do it juuuuust right or you’re pulling the whole field up.
Shado-Pan Monastery is up there for me. Halls of Stone gauntlet is intolerable and also pointless because it’s nearly impossible to fail. Grim Batol as well, since pugging it in Cata on Heroic was damn near impossible.
I am rather surprised at some that did not get mentioned in here for specific reasons, so as I agree already with a lot mentioned, I will add ones I saw get a lot of hate:
Vanilla Stockades–humanoid mobs running and aggroing another room/crappy loot!
Vanilla Uldaman–What do you mean you need to see the enchanting trainer??
Vanilla Zul’Farrak–Oh you forgot to talk to the goblin first? No final boss for you!
Maraudon. Complete dogwater. I get that it was an earlier, formative time, but I despise this dungeon with every fiber of my being. I would rather run Dire Maul all day long.
It’s not a linear hallway therefore people get overwhelmed and whine. That’s pretty much what it comes down to. The actual encounters are fairly standard.