The day we adopted our first cats, we got a Turbo ball for them. Whitey and Billy have never given up on it, for example Whitey found it when he was a year old catten.
Five years after we got the Turbo ball to entertain the two kittens which would be someday be Catzillas, a new generation uses it.
Updated: I thought this was the same unit that Whitey was playing with above; the ball got replaced when we moved and the original ball got lost. However, it appears the original unit (with a bit of paper stuck in the middle) is in the library. (We also have a green one downstairs.)