Whats your favourite?

[companioncube]

SWP > Ulduar > AQ40

Reasoning:
SWP: We didn't have 4 resto shamans and 2 holy priests. Instead, we had 1 resto priest, 1 resto shaman, 3 resto druids, and two holy pallies. So anytime we survived a boss fight, it felt like a huge accomplishment.

Ulduar: Great design, interesting lore, and fantastic hardmodes.

AQ40: Popping that eye after weeks of work just made those hours wasted all worth it.

[Doz3r]

Can't really pick a specific one so I'll do one per expansion(and one for vanilla);
Vanilla: Probably AQ, both of them
TBC: Probably Sunwell pre-nerf, I love bashing my head into the wall for hours at a time
WotLK: Definitely Ulduar, I just loved my raiding guild during this period and the progression opportunities were amazing.

[t3hg0]

swp best and only the lk hm encounter was great

[Cane]

AQ40, dunno, it was long and annoying but I just loved the epic feeling of the place.

[SprayPlaster]

Instances:

Deadmines, Shadowfangkeep and UBRS. Deadmines was the first instanced that I entered. Went there accidentally with a friend and we were both noobs at that time. Died a lot of times there lol. Didn't know what an elite was so both of us tried to solo a few mobs each. SFK is just awesome. UBRS is like a mini raid, I really enjoyed instances that don't last only 10 mins.

For TBC I guess it's Hellfire Ramparts as I boost lots of my friends multiple times there so I have lots of memories in that instance. None of the other TBC instances really stick out to me sadly, same goes with WOTLK ones.

Raids:

ZG definitely for Vanilla, awesome scenery. Karazhan takes the cake for me in TBC, never got tired of it even till now. Ulduar for WOTLK, again, very impressive scenery.

[Agapyr]

Really hard to pick just one...
Vanilla - Stratholme (not really a raid but did you ever do the Baron run with lvl 60?)
TBC - Kara (I just loved this raid and Moroes dropped Mungo 2 weeks ago, don't know how often I came up short on this one) + Zul'Aman Time run
WOTLK - ICC > Ulduar (very close, both raids have some interesting and sometimes really challenging mechanics) Maybe Halion HC but can't say yet.

[SCeasar]

Going to have to go with vanilla here BWL, good times and we made pretty quick progression. And then there was AQ40.....good lord, the trash mobs before twins made me sad

[LegendGold]

Molten core & onyx

[Nightasy]

I'd honestly have to say BwL from Vanilla, it was my favorite I believe because of the people I raided with more then the actual content. But the content had some fun things with it. Like you could despawn your warlock pet when it got the debuff and then go blow up the IF mailbox bank toons. Good times.

[pauk]

I think Ulduar looks pretty epic, but i like BRD aswell

[[Z]em]

Ok my new Favourite instance is Grim Batol, dont know why. i think i just like the style of it.

[drunkmental]

Icecrown, due to Lich King 25 man heroic encounter which we got down after plenty of tries with 15% buff. Was such a relieve, didn't raid cataclysm hardcore thought, just done few bosses in raids and it was alright.

[2dgreengiant]

Wc .

[freeman725]

UBRS hands down. I hated it, and it, in turn, hated me. I ran that place about 3298394548 times trying to get the dreadmist robe on my lock, but, the good memories outweigh the bad ones. Skipping over the beast and having our pallies drop out because of it was always fun. Getting to the rend event and having the whole front-end of the instance agro us because people forgot to dismiss their pets was fun too. The rogue stealth strategy in the rookery was the only way to do it (in my mind). Hunter kiting drakk and hearing "I'M DEAD! HE'S COMING BACK!" on vent was also great. Friggin good ol' days.

[kymo09ii]

AQ40 clean, clean, clean and wtb last boss is an eye that was cool at first run