My least favourite MMO trope is the thing where you have to fight your way to the end of a long public dungeon that has really dense mob placement where you have to be really careful about your pulls... and then you have to fight your way back out again through all the respawned mobs instead of just porting out because one of the quest stages requires it... and then you have to go back into the SAME dungeon AGAIN later on because the next quests in the chain also take place in there.