If you are talking about a fun home design, then this three-story house designed by Kazuki Nakamura and Kenichi Izuhara is the one of the best design that worth your attention.
Each of the level are connected with a long side from the upper ground to the lower ground and continue from the top story to the lowest story. Then you can find a regular ladder at the opposite direction of the slides where you can climb back to the top level for another slide down to the lower ground.
It’s just like a rat race where you can have a never-ending run circle until your stamina fully depleted. Kids would love this house more than adult. But the idea to include a book shelves along the hallway is really pulling me in. Love that bunch of shelves where I can stuffed in my personal manga collection.