In Zul'Drak there is a quest chain amongst the Knights of the Ebon Blade. Starting with An Invitation, of Sorts... - Quest - World of Warcraft and ending with Betrayal - Quest - World of Warcraft in which you will have to kill Drakuru while taming some very strong Troll.
Where that quest takes place, on top of a necropolis, amongst the sides there are 12 geists, stacked in packs of three each. These geists will always instantly respawn when killed so you can effectively just aoe or single target kill them down yet always have mobs on you to go.
Killing them while the event is active up there is not a feastable alternative however, since during that time you take AoE damage from the boss in the center. So either finish the event yourself if that happens (it will not finish the quest for you) or fly there (in which case the event won't even trigger), or use your amulet to become friendly with him and he eventually despawns. Regardless its best to do this at night so you don't get your grinding interupted
There is a kicker to this as well. If someone is starting the event while you are grinding, you can use your scepter to tame one of the trolls, then proceed to use your amulet so you become friendly with the scourge. Stay out of the fight and keep yourself friendly, for as long as your are friendly with them and out of combat when the event ends, you will keep the troll. This troll hits for 4-5k a hit so you will very rapidly kill the never ending spawn of geists, just make sure you get a hit on them yourself since if a pet solo kills mobs, you get no experience. The troll also has an ability that will heal you, making him ideal for grinding. However it will sometimes lose control but you can just retame it if that happens, eventually he'll disappear however.
http://bayimg.com/image/dampoaabb.jpg
by kanske