Yea, we use the black kong. Haven't tried any other color since the black one is suppose to be the strongest.
As Citygirl mentioned, the jolly ball is great. However, Casey, our pit mix, can pop the dog ones in a matter of days or a couple weeks at most. We get her the big horse jolly ball (yea, the one that is over a foot in diameter). She LOVES it! The black kong is the inside toy and the horse jolly ball (which lasts 6 mos to a yr) and her basketball are her outside toys.