- All class quests!
- i liked the quest line in New Hearthglen (Dragonblight)
- the Murloc suit quest line (read the quest text, it's good fun)
- the onyxia attunement quest (now unnecessary, but still available)
- Thrall's grandmother quests line in nagrand.
- the wrathgate quests (as you mentioned)

[Edit] did you mean WotLK quests only? i added a few i remembered and loved from pre-Wotlk.