Favorite 5 man Instance of all Time

[Geckomayhem]

This is difficult. As with some of you, I've been playing since vanilla, but my recollection of the instances isn't too shabby. I can't really say that one instance in particular stands out for me, but I'll do my best.

Vanilla: Maraudon, Scholo, Strat Live and Upper Blackrock Spire.

• Maraudon was really diverse and is split into three parts: orange, purple and the waterfall area. Unlike a lot of people who had trouble finding their way around, I did it enough to familiarise myself with all of the areas, and enjoyed almost every part of it.
• Scholomance was very cool and actually somewhat challenging in low level gear. I especially liked the four bosses down the bottom that you had to kill to bring out the schoolmaster. And who can forget trying to pull Rattlegore without adds.
• I preferred Strat Live over the dead side. Firing the cannon was cool and I prefer fighting humanoids over undead. Can't forget about Timmy the Cruel, either.
• Lastly, UBRS has to be in my list. Sneaking past the eggs, killing Rend, the Beast, kiting Drak - it's an epic instance.

The Burning Crusade: Mana-Tombs, Shadow Labyrinth, The Mechanar, and Magister's Terrace. Outland had some truly challenging dungeons, especially on heroic. They were also very fun with great boss mechanics in most. Shattered Halls comes in second place because I enjoyed the gauntlet, and the other two Tempest Keep ones also come in second place because they were fun.

• Mana-Tombs was challenging. Like a lot of TBC instances, CC was quite important. I liked the bosses, especially how difficult Nexus-Prince Shaffar was, and the escort quest made you clear the whole instance before attempting.
• Shadow Lab - Fun with party-wide mind control (Blackheart), kiting Vorpil away from the shades, and then there was Murmur's room. What a challenge to clear! I liked doing Murmur on heroic. It showed how quick people's reactions were.
• The Mechanar - no one liked the Sepethrea fight. Those elementals did some serious damage! Pathaleon was a real challenge too. The whole theme of Tempest Keep with its glowing lights, Draenei architecture and abundant magic was a great experience.
• Magister's Terrace was obviously added in the Sunwell patch, near the end of this expansion. It was definitely challenging. The randomness of Priestess Delrissa's companions and the anti-gravity phase / burning down the phoenix of the Kael'thas fight made for real challenges.

Northrend: The ICC dungeons. Sure, other dungeons have their appealing fights, such as transforming during the Tharon'ja battle, or -all- of the fights in the Nexus - which makes me consider that the Nexus is probably my second favourite instance area; including the Malygos fight. But the ICC dungeons are polished and the theme of them circulates around the core of the expansion: the Lich King's presence is palatable. They are about as challenging as Northrend dungeon content gets (which isn't saying much, really), and the boss fights have some fun mechanics. The Halls of Reflection gauntlet is much improved over the Shattered Halls one from the previous expansion.

[saberon]

I liked all of the hellfire citadel isntances.

I'd have to lock in this. They were amazing.
Favourite would probably be Shattered Halls (Heroic) (The version that was around at the time of TK/SSC). The original was absurdly difficult and the final version was mind-numbingly easy/boring (aka just like all of Wrath instances), but there was a large chunk inbetween were it was challenging AND fun.

As for favourite wrath, i'd say Azjol-Nerub. And for vanilla... a toss up between scholo and strath dead. I sure did love those scourge zones.

[Spinz]

Vanilla has to be probably whole Scarlet Monastery

The Burning Crusade - Caverns of Time Escape from Durnholde

Wrath of the Lich King - Azjol'Nerub

[Rocap]

SFK
H-MGT (Played a hunter, miss the CC, honestly I loved controlling that place)
Cant pick one for wrath, not because I think they sucked. They all pretty much had a good feeling going on. None of them really being hard, but they didnt get boring until LFG turned into what it has now (not a bad thing) just got burned out on them all way too fast.

[Cyphran]

Vanilla wow. Scholomance. I loved that place to death. It was hard, you could aggro-wipe the group very easily, there were so many quests. The blood needed for the bat boss was cool. Jandice was such a whore (took me ages to get my Dreadmist). Scholo had it all... I recently went back and tanked a Full clear of the place for a bunch of level 50somethings on my 80dr00d.

BC instances... H.Botanica and H.Arcatraz. For similar reasons to why I liked Scholo. These two instances were tricky. Bot had plentiful damaging trash that required CC and positioning!!.... Arcatraz had single mob trash packs that hit harder than most bosses. That... and the first boss on heroic could be very messy. I really liked H.Mana Tombs for the same reasons. Had the key for the optional boss there too

Wrath instances... everyone is heaping shit on them, but I remember then from 2-3weeks after launch and I LOVED the Culling of Stratholme. My friends and I worked our goddamn ASSES off for our Culling of Time drakes. I was healing back then, and it was just plain Hectic, you try speed clearing with a sub 20k hp tank and 3 dps who pull less than 1k each. My mana wasn't epic back then either. We were constantly falling short by 1min to 30seconds. The first Infinite Corrupter kill was delicious. We *just* failed it again he next day. Wrath heroics were excellent in the gear you were expected to be in.

[Raegwyn]

shadowfang keep, BRD before bc came out, and ramparts