Kara. I fkn LOVED that raid. We were a small 10 man group that had just splintered away from a much larger guild. Most of us were RL friends that were sick of the drama.
And I was such a bad player back then that as a paladin, I had a hybrid Ret/Holy spec with a few points in Prot. I was trying to heal like that, with a 2h mace. My gear was a mix of dps plate/spell plate/agi mail.
Icecrown Citadel was my very first raid. I got shivers the moment I entered the place. It amazes me when people complained that the raid was out for so long cause I've never seen a single raid that was run as often as ICC since then. Even these days, its not hard to miss a ICC run.
There are probably a few raids that are just epic in proportion.
Um depends on what we really consider a raid. Technically I raided pretty much every max dungeon for months because people rarely 5 manned Stratholme, Scholomance, BRD etc.
First time I was ever in a raid group we 20 manned BRD with people ranging from 48 to upper 50s. People still died because of aggroing things they shouldn't and half of the raid got caught in the massive respawning dwarf room with no way to get rezzed.
Not going to count BRS as a raid so real first raid was a couple weeks after launch in MC (obviously). Had lots of 58s and took 6 hours but killed Lucifron then proceeded to wipe to the trash to Magmadar for a couple hours. Both items off Lucifron ended up being rot because it was lock/druid loot. There were zero locks in our raid and the only druid (who was 58) disconnected and was ineligible for loot.
The first raid I was ever in was Molten Core. I had done 15 man UBRS and 10 Scholo / Strath before that, though.
I wound up in this guild on Shattered Hand called <Drama> by complete accident. I had some friends beat me to 60 who had joined up with them previously. They convinced the GM, a guy by the name of Daedalus at that time, to invite me (I was playing my Warlock then as my main) based solely on the fact the guild needed locks. Back in that day, Warlocks were drastically underplayed. Anyway, they invited me thinking I was level 60 when in reality I was only 46.
Fast forward a few weeks when I hit 60 and I got a whisper telling me I was needed for Molten Core. I had no idea what that was at that time. The guild officers ran me through the attunement in 15 minutes and we cleared the whole zone. I was in total awe. That moment is when I knew I wanted to raid.
I spent three years with Drama as one of their main raiding Warlocks. We were decent enough to get the World First Nefarian kill in BWL.
As for my first PROPER-Professional raid with a guild it was Karazhan! I felt it was an achievment beating the first 5 bosses, ..eventually I beat them all a week later, but that's not the point. :P
One of the first 2-3 runs of my first raid (judging by the time played), if not the absolutely first...
The UI - every time I see it now, I facepalm for a minute I had like 3 different addon packs installed...
UBRS on my pally, got my shoulders from the Beast on that run too. Good times. First raid with purples was Kara, also on the pally. Got the healing mace from Prince that run also. I've never been that lucky with drops since
Level 80 Naxxramas on my Hunter. Fun times. I used to pug every week 25 man and got all of my cryptstalker and the bad ass gun from KT before I started raiding with an actual guild.
Wrath baby here so Naxx pugs for me as well. Got into a raiding guild and started tanking for Ulduar. Game hasn't felt as epic since those first few weeks of Ulduar.