Pull the world.
I've developed a love for bosses that call the remaining mobs to them when attacked. SM cath is a great example. Pulling Morgraine will aggro any mobs left in the cathedral area. This makes in a great farming instance.
A greater challenge is the emperor in BRD. He calls the throne room to him. This is roughly 60 mobs, maybe more, though most or non-elite. This is a great way to get a wide variety of old-world items such as runecloth, greens to DE, and dark iron residue and scraps.
Tonight I tried Eranikus in ST. Unfortuantely he cannot just be pulled. Instead you have to kill the troll boss and his add. That means killing the 6 mini-bosses in the ring. They are easy enough, but sme trash is impossible to avoid, wasting time. As a small condolence, the troll boss will call the nearby mobs to help him, making for a decent pull of 20-30 mobs. This is balanced by his attempts to MC you, which if successful will cause everything to reset at full health, and may cause the mobs from furthest away to reset entirely.
I finally got to Eranikus after perhaps half an hour. I pulled him and then waited. And waiting. And waiting a little more. It takes a long time for the adds to arrive, but once they do, it is a few dozen dragonkin, whelps, and 2-4 drakes (in my case two since I accidentally killed the other two on the way to Eranikus). My frame rate went negative, actually stealing frames from other people to make up for the deficit. The lightning effect from force reactive disk didn't help either, but the damage is amazing.
I really need to try sneaking over to Garr someday. I'm going to need some more block value.