Pretty easy. You have to build 3 rankings : the "YAY !" ranking, the "Meeeeeh" ranking, and the "FUUUUUUU.. !" ranking, based on your average reaction when you see the LFG daily dungeon loading screen. No need to gives explanation.
Reminder : choose wisely between Utgarde Keep, Utgarde Pinnacle, The Nexus, The Occulus, Azjol Nerub, Ahn'kahet, Drak'Tharon, Violet Hold, Gundrak, ToC, Halls of Stone, Halls of Lightning, Culling of Stratholme, Forge of Souls, Pit of Saron, Halls of Reflection
Here's mine :
"YAY !"
1. Azjol Nerub
2. Utgarde Pinnacle
3. Forge of Souls
"Meeeeeeh"
1. The Nexus
2. Drak'Tharon
3. The Occulus
"FUUUUU... !"
1. Halls of Reflection
2. Culling of Stratholme
3. Ahn'Kahet