What are some unusual features that would be great to add to a new home under construction?

I think about this subject a lot and I pin my thoughts so I have them handy:

Page on Pinterest

Sunken Living Room- this is my dream for entertaining.

Sunken PreFab Wine Cellar

Hideaway Parking Spot that leads to your underground garage and bunker

Sunken Tub 

Backyard Movie Set Up

Fish Tank Bedroom

Halfway Decent Tree House- this will cost nothing if you have your contractor do it while building your house.

Hanging Bed

Multi Purpose Table

Hidden Rooms

Nooks, lots of nooks

I hope some of these things are what you were looking for.