So much room for activities. but little, individual reading/working nooks (for a tea house or library.) -- or just a space to crash/decompress/work in a different position. And the scene from step brothers makes it even better!
Lofted beds with walk-in closet underneath. Good when you're short on bedrooms for all of the kids. Loft beds and instead of a closet underneath, it could be the kids "rooms" for private and quiet time.