Ok, let's be more cheerful.
My favourite room, now sadly dismantled, was a simple 4.5m square space. There was an elegant pair of tall doors opening to the garden, a late Georgian Parian marble fireplace, old oak floor boards, and a ceiling height of 3.8m.
I was incredibly poor, but had a lot of books. In awe of the the rather grand architecture, I built a bookcase that filled one whole wall, copying the mouldings from the door and skirting.
The room was a lesson that I forgot. Just a wall of books, two or three good chairs, and a table. The walls were empty, except for one large and important painting (a good principle to remember)
I went back to that room a few years ago, because it was such a good space. I don't do sofas (I own a small never sat on Corb thing) and time has taught me that books and maps, and a chair for your friend, these are things that open the imagination. You pull out a book, a conversation starts, you share memories and ideas, a few beers, and new adventures might begin. I don't think a big flabby sofa is quite the same.
Edit: this is why I suggest that you get rid of everything that lurks in corners, and be absolute about the things you love. It might be three or four bikes that you can hang on the wall, but flatpack oddities storing never watched dvds should go.