http://www.kongcompany.com/worlds_best.html
The Kongs are pretty awesome.
This is the only toy we have found that was practically indestructable.
The older versions had a hole in the center you could put treats in. It is the only toy my uncles English bulldog could not destroy.
My mom bought one for her chocolate lab and it is the only thing she cant destroy.
They make them in quite a few different sizes as well.