I haven't seen those being mentioned before, so i thought i'd share them with you (tested on a frostmage).
#1 Thor Modan:
Inside of the keep all mobs are melee and can even be pulled while riding, since even though this is a building, you can ride inside.
coords: 66,6 15,5
#2 Cultist encampment:
In the sholazar basin there is an encampment with cultists, you can aoe farm those pretty good once you consider one thing: they have sort of a ranged attack (they throw a bomb) BUT it ain't targetted, they throw it at the ground where you stand and you have 5 seconds to move away, plus the range is only 'bout 10 yards i'd say.
For me as a frost mage they're piece of cake.
coords: 56,5 42,1