perfectionist

Short definition from Wiktionary

Noun

1. 1
   Someone who is unwilling to settle for anything that is not perfect or does not meet extremely high standards.
2. 2
   Someone who thinks that religious or moral perfection can be attained in this life.
3. 3
   One of the Bible Communists or Free-lovers, a small American sect founded by J. H. Noyes (1811-86), which settled at Oneida in 1848, holding that the gospel if accepted secures freedom from sin.

Adjective

1. 1
   Demanding perfection; being a perfectionist; imposing overly high standards.
2. 2
   Inclined or related to perfectionism.