I have never seen a quest that brings out the worst in players than "Junk in My Trunk" in Utgarde Pinnacle. For this quest you must gather items laying around the instance. There are not enough for a full group on the quest to pick therm up on the same run, so many people jockey to be the first to get their junk. The first time I ran that instance I was amazed at how greedy people would be. The tank would pull but the healer was off picking up a silver bar or a bauble. You guessed it, wipefest.
It almost seems like a social experiment on Blizzard's part. There are other quests where you have to pick up stuff in instances, but this one seems somehow different. How would you handle a group member who shirks their responsibility in favor of sparklies?