Laundry wise:
Laundry tub (very useful for messy children and objects)
Washer/dryer on the second floor or a dumb waiter and/or laundry chute
A large linen closet with shelves
Front-loading washer and dryer high enough I don’t have to bend
Master bath wise:
Large multi-person tub
Shower with safety bars (large enough for multiple people)
Instant hot water
Kitchen wise:
Holes in the countertop for garbage and recyclables (just slide the filled containers out).
Oven at non-bending height
Broiler
Gas and electric cooking
Silent multi-rack (configurable as needed per load, like a fridge with movable shelves) dishwasher
Instant hot water
Living room wise:
Built in bookcases and large windows
Baby Grand Piano
Built in window seats
Family room wise:
Built in TV holder (entertainment center) that can close up and look like cabinetry when not in use.
Game tables that configure to different games
Regulation Pool Table and mini bar
Master Bedroom wise:
Bookcases built in and above the back of the bed
Recessed lighting
A phone that flashes instead of rings
Skylight
Garage wise:
Rotating storage racks, that act like a Ferris Wheel. You put your stuff on a shelf/in a bin, and it rotates up out of the way, you use a keypad to pull it down when you need it.
Overall house wise:
Optional drainage. I’d love to have my shower water, Laundry water, etc, optionally drain to a private greywater well for re-use on the lawn. (I’d stick to organic shamppos and soaps). You know, flip a switch and it drains to the common sewers or not.
Solar heating, electricity, wind electricty
Large trees to provide natural shade and cooling for the house.
A breakfast room with a glassed in roof that can be cranked back to let the fresh air and sunshine in (my aunt has a room like this).
A cat door that doesn’t look like one (and only works for our cats via their ID microchip).