completist

Etymology 1
. Originally from, the slang of science fiction fans.

Noun

 * 1) A collector who strives to obtain a complete collection of some type of thing, especially a fan who aims to own or consume the complete output of a particular author, publisher, musician or band.

Translations

 * French:
 * Italian: completista

Adjective

 * 1) Which attempts to collect something completely.

Noun

 * 1) A person who champions any philosophy which focuses on the completeness of something; as, a completist philosopher who holds that a definite complete body of knowledge exists to be discovered

Translations

 * Italian: completista