Not totally broken games but with some powerful items.
I can't expalin it very well but retail WoW is such a "normalized environment" where everything is fixed for the sake of balance that nothing is exciting.
In Vanilla we have crazy items like "Manual Crowd Pummeler"a lvl 20 item that is used at max level. People would farm this item to have several of them and use the 3 charges for imba DPS.
Some potions were also overpowered like "Free Action Potion" to make the lives of Mages and Rogues miserable.
Engineering was the best profession for PvP and gave you a HUGE advantage.
Wolfshead Helm was a level 40 item, best in slot for feral druids. Better than epics.
I don't know, there is some kind of flavour to this types of stuff that were the result of the game still being new and poorly balanced.
EDIT: I don't think Vanilla was completely broken. It just had SOME stuff that could be abused and that makes it so much cooler IMO