Something from Arby's. Your choice.
I'd probably eat anything that wouldn't destroy my health right away. So like no bleach, or cleaning products, glass, or something that would cause me to choke.
On the other hand the I think the most disgusting thing I would eat would probably be some sort of side of the road animal that been laying out in the sun for a day or two. *Barf*
A car, or a boat
As long as it wouldn't kill me, I don't give a damn. For 1mil? Do your worst.
Hell, even if it could kill me...and it acted slowly and I had time to go to the hospital, I'd still consider it.