1. Halls of Stone
2. Trial of the Champion
3. Oculus
4. Hillsbrad
5. Black Morass
6. Halls of Reflection
7. Throne of the Tides
8. Halls of Origination
9. Gnomer
10. Violet Hold
Reasons of gauntlets, vehicles, waiting, elevators, waiting, and RP.
Oculus: Enough said
H. Deadmines: Long, terrible dungeon. Awful gauntlet, annoying bosses, too much trash
H. Stonecore: Just for the corridor before Ozruk, and Ozruk himself before they added the visual for Shatter
H. Zul'Aman: Long, difficult, and lazy. At least ZG was a total redesign but ZA was basically the same exact place as the old raid with a different model at the end that did the same things as the old model.
H. Halls of Reflection: Gauntlet was awful at first. Great lore, awful implemntation.
Honorable mention goes to Grim Batol because of the annoyingly stupid trash and gimmicky bosses, and the hard DPS check on Erudax. Also ToC for the jousting part.