I was previously on Nagrand, then moved to Jubei'Thos (As Alliance) all because of friends. After I quit they moved to Frostmourne. If I was to play again I'd Frostmourne-Alliance.
Favourite raid by far is Ulduar. I loved it, and the hardmodes. I did them when they were current so getting the DPS check and everything was tough. I remember killing XT002 "Heartbreaker" after he enraged with just me and our "tanking" Rogue still alive. Getting a 100k+ Windfurry crit on Hodir to with the buffs and more, was great. Not to mention Yogg-Saron sent chills down my spine with his "I am a lucid dream, the monster in your nightmares....The fiend of a thousand faces. Cower before my true-form! Bow down before the god of death" and his evil scary laugh on-top.
I miss it in one sense, in another MoP was a massive blow for me and I wish they'd release old-school servers based on BC/Early Wrath Mould (Come ToC they made the game too easy). I loved it back in those days, I know people say to me "Just go private server" but it's not the same feel, experiences and finding a raid or BG is hardly doable (Yet alone stable servers).
Here is a link to my main:
Meralus