I wrote a whole post about swapping your bookcases for wall-mounted shelving. Wall-mounted shelving takes up less space, and can almost appear to blend in with the wall. Image from Stadshem, via Freshhome.
My dream is to have a room(s) filled with books -- books as decorations! But if this was my room, I'd have to straighten that stack there on the right. Love that cozy chair/ottoman! Perfect in this reading room.