Peter is the disciple we have the most information about from the Gospels and book of Acts. He goes through a long character arc and, as a result, is a person many people feel they can identify with as he traverses the ups and downs of faith.

John 21:2-3 2 Simon Peter, Thomas (called Didymus), Nathanael from Cana in Galilee, the sons of Zebedee, and two other disciples were together. 3 "I'm going out to fish," Simon Peter told them, and they said, "We'll go with you." So they went out and got into the boat, but that night they caught nothing.