Keeper of the Lake - I hate the aesthetic, I hate the boss fights, I hate the blaring alarms that go off.
I would have usually picked Aurum Vale as a second but I'm starting to hate it less. I think:
Haukke Manor - The dungeon itself is fine, it's just most classes aside from the tank don't have aoe at this level and 1 , 2 ,3 each seperate add is just tedious.
Which dungeons would you blacklist - and why?