The Black Temple] of course!
Icecrown citadel is my favorite raid, and the forge of souls is my favorite dungeon.
Black Temple is my favorite instance,spent so many times in there with my friends.. :)
Has to be old Deadmines - Brilliant first shot at group content.
Favorites:Dungeon -> Trial of the ChampionRaid -> Ulduar
My favourite instance in WoW is the Well of Eternity
ulduar: the train ride is one of the best things ever implemented and kologarn is one of my favorite bosses
I always loved Naxxramas
Definitely Molten Core.
"See your world through my eyes: A universe so vast as to be immeasurable - incomprehensible even to your greatest minds"Ulduar is still unmatched!Goosebumps everytime I face Algalon!
Favorite instance: Scarlet Monastry - so many memories running from SS as a NE in Vanilla WoW. Love that place - such a great vibe in there.
My favourite is the good old Wailing Caverns
My favorite instance is Magister's Terrace. The atmosphere and the music are great, there is awesome loot to collect and my favorite boss with the best in-game quotes is there. Tempest Keep was merely a setback!
Old Hillsbrad, Well of Eternity, Grimrail, in that order :D
Just loved old Blackrock Depths - such a long, complicated instance with many secret chambers, and SO HARD to remember without a map. Was a great time clearing all the floors of this enormously attractive (for me) place.
Dragon soul for sure!
I honestly have to say Icecrown Citadel is my favorite instance despite starting to play wow on the very late MoP. The building is massive! and the instance had the potential to be even bigger consider all of the rooms which was not used.
Black Temple <3
Ulduar is by far my favorite visually, but I really enjoy the bosses in Blackrock Foudry.