Well, I'm gonna have to say my favorite dungeon is still the original, Worgen infested Shadowfang Keep.
My fav raid is Icecrown Citadel & my fav dungeon is Halls of Lightning
It's a very hard decision, but I think Icecrown Citadel would have to be my favourite, simply because it's the epic conclusion of the storyline from Warcraft III that initially got me into WoW.Any dungeon/raid that I've spent a lot of time in I generally have fond memories of though (with some exceptions... lol)
My favorite instance is Stormstout Brewery, home of the best brew and the warmest reception.If it wasn't overrun by monkeys, rabbits and floating beer monsters.
Utgarde Keep - I love the atmosphere in all Northrend instances but this one is my fav. Indoor/Outdoor combination is awesome.
Blackrock Depths still hasn't been topped.
My favorite instance would have to be Ulduar.
Although this place gets a lot of criticism I still hold great affection for Dragon Soul, it being the first raid I ever entered. Having gone through some old content however I must say I love Ulduar it is simply epic I wish I had been playing WOW when this one first came out
That be Karazhan for me, especially the lower part. All those passages and interlinks between areas, could easily make you get lost if you decide to wander around.
My favourite instance, hands down, is Karazahn. We spent a lot of time in there back in the day - even after the main group had finished it and moved on, I was still leading other teams through to gear them up. I don't think I ever got sick of the place.
with the exception of the pointless wind section I actually enjoy skyreach.
Definitely Magisters' Terrace!
My favorite instance is still BRD. It goes on forever, and I especially love the dwarfiness of it. I always stock up on Sulfuron Slammers when I'm there--it was the only drank in Vanilla to get you totally wasted in two shots! (Hail Eris)
I would have to say Shattered Halls, it was a challenge back in the day.
My favorite instance is Firelands... Best memories are from there...
The Shattered Halls brings back many fond memories.
The Culling of Stratholme has to be my favorite instance. It brings me right back to WCIII and when I fell in love with the Arthas storyline.
Hellfire Ramparts
Favorite instance is Stratholme. Great lore and story in there. Favorite raid is Ice crown Citadel.
My favorite instance is Naxxramas!