If you're in medium levels Sandsea is the most useful I've had.

Then if you're really need for the money in the part of the game, Ozmone Plains, chain those Wus just ignore everything else. Only Wus.

Feywood comes next as the Mirror Knights or whatever the walking owls they were. Dropped the Mirror stuff. Those are pretty damn useful. And when you learn to walk around correctly, chaining isn't going to be a problem, meaning you get 99 of everything they drop fast. Whenever you need the money, those are what I'd chain.