Shaman, back in Naxx. Can't even remember what kind of deck I used.
Priest followed in GvG, exclusively with Mech Priest. One of the most fun decks ever. Then Warrior as Control and Mage as Secrets.
Paladin followed in WotOG with N'zoth. Now working on Rogue, as both Mill and a Shaku/Jade hybrid.
Meanwhile, Hunter isn't even level 50 yet >.>