I've got a 9 month old black lab puppy and a 4 year old mutt.  The lab likes to chew (don't they all)!  Can anyone give me some recommendations on good durable chew toys?  We have a few Kong toys and they hold up pretty good but their selection is so big I don't know where to start for additional ones.

The lab can devour a 12" rawhide chew stick in an hour or two.  The mutt likes the Kong toys filled with peanut butter.  Everything else he lets the lab have.