All one level - at least, master suite on main level. An elevator, if it’s two (or more) stories.
Backyard pool - like the sort you see them building on TV shows, not a rectangular lap pool. Heated, so we can use it during spring and fall. I like the idea of an indoor/outdoor scenario but I hate the chlorine-y smell of indoor pools - maybe a saltwater one would do?
Bigger kitchen with two dishwashers. A large walk-in pantry with 3 times the space of the one we have now (normal “two-door closet” size). Not that we’d necessarily need 3 times the food - but twice the food, with enough space to SEE everything…
Garage(s) with enough room to park the car AND walk around the cars - the standard 20 x 20 foot garages these days don’t have enough room to store extras like bikes, lawnmowers etc. and we can’t get from one car to the other without opening the big garage door. At least 3 cars worth.
Heated driveway and sidewalks, to make snow shovelling easy (or not required).
Solar panels so we can be off-grid for electricity.
Bathrooms: roll-in showers in case we ever need that. Walk-in bathtubs, ditto (I love the huge tub in our master bath but it’s a pain to haul my fat carcass to my feet after a long soak). Grab bars to assist with that. Whirlpool tub. Bidet toilet with unlimited warm water (the seat attachment we have now is nice, but the warm water only lasts a minute or two).
A library would be great. 30+ years ago, there was a house built “on spec” in a town we used to live in. It had a 17x17 foot mahogany-shelved library - supposedly the single most expensive room in the place. The price for the place was exorbitant (by our standards, then; our house now in a more expensive area would sell for about as much as that place 30 years ago). We got rid of many of our dead-tree books when we moved here 18 years ago, and I mostly read on my Kindle (thanks to aging eyes) but there’s nothing like being able to pick up a book at random and start browsing.
A view of some large body of water - ocean, river - with access to same. A couple years ago we stayed on Ile d’Orleans for a few days and there was a riverfront lot for sale nearby. It was really tempting, except for our lack of a) funds, and b) time to spend there.