So what are the toys that never get old? In my experience these are the toys I would suggest for both girls and boys.
First is an easel. The hours of fun that kids get from creating masterpieces lasts from as soon as they can dip their fingers into paints until well after they are beginning to take art classes. As a parent, I still like to paint using the easel sometimes.

Second is block puzzles. In the beginning kids chew on the blocks, then stack them, and then later discover the ways to put them together to create the scene. Afterwards, they get joy from making funny disjointed pictures. My block puzzles lasted from age 9 months until 10 years old for fun.

Third is a parachute and some bean bags or bouncy balls. When kids are young, you can make it work for them. Blowing bubbles or bouncing balls and letting them crawl through the billows on top. Then you can make it fly like a tent and let them run under, and when they are older they can do it themselves and try to balance the balls or bean bags on it by themselves. They can also be used to make forts.