Wow, the hunt for the perfect toy! Gives me memories too.
Naboo has this ball she just loves so much, even sleeps with it.

I had bought her many other different brands of balls because I had forgotten where I've gotten "her favorite ball" because I was so afraid she might lose it.
Then one day I went to ikea and low and behold, there was her ball! It came in 3 sets for $1.49!!!

I must have bought her 20 sets of them and yup she plays with all of them.
I attached a picture of the ball in case anyone is interested.