From Wikipedia:
Messier 74 (also known as NGC 628) is a face-on spiral galaxy in the constellation Pisces. The galaxy contains two clearly-defined spiral arms and is therefore used as an archetypal example of a Grand Design Spiral Galaxy.[4] The galaxy's low surface brightness makes it the most difficult Messier object for amateur astronomers to observe.[5][6] However, the relatively large angular size of the galaxy and the galaxy's face-on orientation make it an ideal object for professional astronomers who want to study spiral arm structure and spiral density waves.