And for the sake of the question, I'm not looking for "I'd like to have 10 extra bedrooms and a 9-car garage." I'm aiming for something that you could reasonably do, but would require some planning. Something that doesn't benefit from spontaneity. Like moving the fridge, which would likely involve moving some cabinets and running a new water line. Or moving a door.

In our house, we have two entrances. First, our front door, which is the canonical entrance to our house. When guests come over, this is the entrance they use. However, my wife and I ever use that door. Instead, we opt for the second enterance: the door from the garage into our house. My problem is that these two doors are on completely routes through the house.

As you can see from my very crude, not-super-accurate drawing, one must walk all the way through our main floor to get between the doors. Now, that wouldn't really matter except for:

When guests come over, this is the entrance they use.

That means that if we wanted, for example, a coat rack by "the entrance", we'd need two. One for our guests and one for us. Or when we get home we'd have to go All The Way through our house to deposit our coats, which surely isn't going to happen.

Were I able, I would put a door on the perpendicular wall next to our front entrance so that all home-entering is done in one place.