The IKEA Expedit bookcase may be one of the most popular affordable bookcases out there. (When you actually start looking for it, you see it everywhere. Trust me.) Its ubiquity also means it's rife for reinterpretation, as seen in this kitchen/dining storage hack!
Also on these boards
IKEA expedit with recycled wood. A good way to make the expedit fit better with the rest of our decor