Chewing No's
I personally would not give my dogs any bones or treats with any harsh preservatives or that is treated with chemicals, I wouldn't ingest these, and nor should my dog.
Cooked bones, chicken bones, or any thin bones or flat bones likely to shard.
Any object, organic or not, that breaks off in sharp pieces that can be choked on.
Okay Chews
Chews that I have had great success with are:
Kongs, especially if they are filled with peanut butter or some other treat and frozen, kongs can keep a dog busy for hours.
Safe plastic chews that can be bought at any pet store.
Bully sticks.
Real, raw bones from butcher. Though some precautions should be made before giving your dog raw bones, like freezing the bone for a certain period of time.
And by far the most popular chew for our dogs are deer antlers, buffalo horns and any other antler/horn we can get our hands on. They can be very expensive, but if you happen across one while hiking, or hunt, they are fantastic chews for dogs. Deer antlers rarely break in sharp pieces, and one good antler can keep all three of our dogs busy for months.