Mine love the cuz toys, they really arn't picky so as long as it either squeaks, bounces, rolls or can be pulled on. They just love the cuz toys, it is a favorite around our house. My maltese doesn't like any toy though, he won't play with any toy. I take that back, he thinks Scampers is his toy so he plays with him.
Some dogs are picky, luckily mine arn't that picky but I can see where it would be frusterating. What kind of toys does he like??
We got my mom's border collie an IQ cube and can't wait to see how she will react, it will be her christmas present and she loves challenging toys, she thrives for the mind stimulation. Sorry you had such bad luck with the cuz toys.