Oh god... MC? UBRS? Something like that... never got to see anything above that in Classic though, I was too busy messing around with alts and trying to figure out if I could make melee mages viable or not :P
My friend got me into the game, groomed me to raid with his guild from the day I started playing. When I finally stepped into the raid after so much preparation and learning to be a part of his team, it felt like I was a prince, finally coming of age.
Good old Karazhan only got as far as Maiden and tried once on opera event then the guild I was in fell apart then never got back into raiding until Naxx and then when I finally downed Naxx 25 man on a pug it was glorious I loved it so much was such a blast. I don't care what vanilla hipster players talk about downing Naxx 25 man in WOTLK was one of my favorite moments still one of my favorite raids ever.
Scholomance, back when my first Druid hit 60 and it was tuned for 10-Man. Everybody did it with 10 Man instead of 5, because otherwise it would take 200 Hours to complete and was a huge Pain in the Ass. So much fun!
My first raid was scholo 10 on vanilla first week of release...
My priest, still 60, still earned the first epic staff dropped on kael'thas server europe the following days after the first gandling kill. =)
On beta, we runed instances so much....
Was the no-life period...
Hate to say it, but my first raid was Blackwing Decent .. yeshyesh, Cataclysm! (Started playing in Cata aswell) Cleared it full normal and then stopped again.
Then started again in Firelands and killed everything since then in current content HC (except for Tsulong/Sha last tier)