I have never played Dks before so I can't judge blood DKs.
I'd have to say BM monks. Some of the newer ones probably only know how to spam Spinning Crane Kick and Breath of Fire from the back-to-back dungeon leveling.
DKs for being the most derp, that is people consider the players to be idiots
monks for being the "hardest to heal", in this case people don't really blame the players but more blizzard for making monks spiky etc (even through it's often a player error and not a class design issue)