What do you think the coolest quest ever is?
Personally i would have to say Long Forgotten Memories (
http://www.thottbot.com/?qu=8305)
Its such an easy quest but after you finish it plays a Battle of Epic Proportions, its probably one of my favorite quests ever, it shows all of these people that turn into dragons to seal the gates of Ahn Qiraj, if im not mistaken this is the quest you had to do to open the gates in the first place...
But if you havent done this quest you should check it out, you get it after you turn in the head of broodlord if you have appropiate reputation with Brood Of Nozdormu...