"Personally I can't stand bookshelves in rooms."
You would hate our place (the living room alone has over 130 linear feet of bookshelves).
My favorites are open backed "standards" with shallow 5.5" deep shelves as the books just seem to hang in the air.
I installed them on the speaker wall in the living room starting @ one foot above the floor and extending to the ceiling.
Did the same in the main bedroom on the "my side of the bed" wall.
White walls white hardware/shelf material and the shelves themselves are barely noticeable.
DeKay