Hell Andariel also has a decent drop rate, but she's a lot faster to kill with a Fire Sorc.

Blizz sorcs own Meph pretty hard. It's really hard to MF a lot of the good spots with 1 MF character since the patch has made monsters in Hell a lot tougher.

I'd stick with Meph. Pindle can be ok, but you need a LOT of patience.