bibliophilia; bookworm
Refers to a person who loves books deeply, often to an excessive degree. A literary term, rarely used in everyday conversation.
He is a bookworm, and his room is filled with books.
bibliomania; bibliomaniac
A more intense, almost pathological obsession with collecting or reading books. Even rarer than sense 1; mainly encountered in literary or historical contexts.
When one becomes a bibliomaniac, reading itself becomes the goal.