Room size priorities
I love to design houses in my mind. I suspect I'm not the only one who does this.
I was thinking about house size and room size, and how to get the most function for the square footage. I would put the space in the shared public rooms where people gather for the most part, and reduce the size elsewhere.
For me that begins with a large farmhouse style kitchen, and no separate dining room. This is the primary social gathering room (and the only room where I personally would bother to put a television since I don't watch a lot). A big laundry/utility room with windows and space to dry laundry indoors if need be located off the kitchen is important to me. A large bookcase-lined living room with a fireplace would be my other large room. Here is where I would put a a stereo (or possibly a piano if someone in the family plays). I'd love a window seat here, too. It is a room for music, reading, and conversation. It is a shade more formal than the kitchen. Your book club could meet here, or the parents of you child's future spouse, or a committee from your church or school. Easy access between the two rooms for easy passage when entertaining larger groups, perhaps a large archway. However I don't like the complete openness of the true open concept. I find that noisy and confusing, and strongly prefer a partial separation. A small vestibule of some sort with a coat closet and half bath, because I like transitions. As for bedrooms, I know the current fashion is for big, big, big, but honestly, I would just sleep there. It needs to be big enough to hold a bed and dresser and a couple of night tables comfortably and easy walk around room, but really that's all. So this is one way I would save space, keeping the bedrooms moderate in size. I would like at least two windows in each, being a fresh air fiend and a lover of natural light. So a couple of bedrooms, neither too big, and a decent-sized bathroom located between them (not jack-and-jill style, which I dislike). I like a window in the bathroom, too. If the second bedroom is actually a guest room and not for a family member, it could be made a bit smaller. A porch, screened or open, would extend the living area outside very pleasantly to breeze, shade, and views of the garden or neighborhood. If one of the family members has an activity with serious space requirements such as wood shop, sewing room, ham radio station, exercise studio, hobby room, or home business, I would probably accommodate this with a finished walkout basement. I suspect a second television might appear in such a room, even for me! We have such interests (no, not all of them!) so we would do this, but if not, I would skip having a basement altogether. After all, the utility and laundry requirements have already been met in the room off the kitchen.
Anyway, this reflects my thoughts on what appeals to me. No doubt others have their own. What I described would not work for a large family, but (I think) would suit a couple with one or at most two children, or empty nesters.