I'd have to go with tzhaar monsters because they drop the tokkul and obsidian items. Also what others always do (I'm not sure how many still do) are avansies at God Wars Dungeon collecting addy bars. Last I knew.. Avansies were like 500k an hour maybe?
I'd say if you have a high level main, I'd say also try killing the bosses in GDW's, maybe you'll get lucky. Maybe even tormented demons for D claws?
Hope this helped and good luck =]