Books, books and more books! I've always wanted to have a high-ceilinged room with books from floor to ceiling. so high in fact, that you need one of those slidey-ladders to reach the uppermost shelves.
I don't LOVE the rug. but I think the green curtain, built-in shelves filled with books and the (presumably) sliding ladder are wonderful. Its missing a fire place, lots of cozy blankets and an oriental rug!