To be honest with you the when you limit the question to "epic weapon quests" there are only like 3. The hunter one, warrior/paladin one, and priest one But there are also 2 legendary weapon quests with the thunderfury ending in a pretty epic battle.
However, there are many cool class quests that are not weapon related.
Shamans - had cool "totem" acquisition quests that gave a chunk of lore and shit on 4 bag slots permanently which enabled you to drop totems from the 4 element types.
+ It had a cool quest chain that gave you a wolf helm
Warriors - had some cool leveling quests that gave some significant gear increase, the one I remember the most was the weapon you got at lvl 20 if I remember correctly which was a big upgrade for me at the time
Paladin & warlock - Had the cool epic mount quests and easy to get normal mounts
There were a bunch of quests similar to above for each class during leveling or at max level that added a bit of flavor to each class and lore.
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We had 1 really good hunter in the guild who would log into every other hunter's account to do the fights.. We would constantly spam the zone chat and pretty much form a barrier around the fight to try to stop people from interfering during the encounters.. It was always sad when someone saw you fighting something cool looking and just wanted to help and completely fuck up the fight
If they try something like that today, people would troll camp those spawns forever but back then it would get you blacklisted so usually it was an accident.