Jun 12th 2009 2:58PM Vanilla: Ragnoros, just an epic fight overall and it was worth it after collecting the fire resist gear needed for it.
BC: I personally loved the Wizard of Oz event in Kara and High King in Gruul's Lair because I was a fire mage.......I also love all of ZA.
Wotlk: Tie between all of the watchers, especially Thorim and Mimiron. The gauntlet in the Thorim encounter is just epic and fun while the Mimiron encounter is the first multiphase fight that I've seen in Wrath. Flame Leviathon comes in a close second.