I'm sure this ain't the fastest one, but atleast its easy.
Non-rested exp à kill = 1.8k EXP
Group with a lvl 80 non-rested exp à kill = 400 EXP
The mobs keep respawning infront of the gate, and the gaurds are helping you. so you just have to tag them
Location: Infront of the Alliance base in Howling Ford
MAP:
Mobs:
Graveyard: