Oooohhh, can I guess? The ones I'm thinking of both came from Frostmourne. The one I know for sure was the Sindragosa quest where the player had to stand in front of her face and eat frost breaths most the fight. The second may have only been for our guild but the player needing to be the Abomination for the PP fight.
Bunch of wipes from, "Sorry, I've never done this before." Yeah, that's because our off tank always does it. Thanks Bliz for reintroducing Teron Gorefiend mechanics, we sorely missed them...