My idea of a dream house is of a typical Taurus castle.
The entryway is well lit with a hard floor, covered in rugs leading off in each direction. Along the walls are a few vanity items, such as some of my Grandpa's art (I'm saving the priceless stuff for my personal space) and my wife's photographs, and it has ready access to the second floor.
On the first floor, I would have the entertainment areas off to one side, such as the traditional American living room, complete with the brain rotting box. I would also have a fairly large library in there as well. Hard floors with comfortable rugs is still an absolute must. Fake leather chairs would make up the seating area in the library, and soft couches are essential for the living room. The other side of the first floor would have the rooms necessary for living, such as a kitchen, separate dining room, laundry room, and broom closet.
The second story would be split up into two sections as well. Above the entertainment side of the house, I would have two office, one for my wife, and the other for me. I would also have a server room, because I'm a nerd like that.
There would also be a dumb waiter between my office and the library. I would put my office in the corner so that I can have two walls of windows, and do what I can to isolate my wife's office, because she's a photographer, and by the time I can afford a house like this, we'll have enough artificial light that she wouldn't need natural light for her pictures. (I don't expect her to spend too much time in there anyways, unless she's editing pictures.) The other side would hold the master bedroom and a guest room, both equally as large, and with laundry chutes, but no dumb waiters connecting to the kitchen, because, by golly, if you're hungry, go downstairs.
Also, even though the upstairs would be carpeted, I would make the floors rigid and thick enough that they didn't squeak... That's important to me as well.
Even though this is my dream house (and I've obviously put a lot of thought into it), there are many other things that I would want long before I even though of making this particular dream a reality, and few of these more important dreams are as physical as the house would be.