Badass Nickname: Jesus gave him the name "Peter", which is from the Greek word for stone, "petros" ("cephas" is another Greek word meaning the same thing). How cool must that have been to have Jesus call you "Rock"? (Though, to be fair, Jesus was also quick to point out when he wasn't living up to the name.)
Character Development: Post-Pentecost, Peter becomes the new leader of Jesus's movement and gains maturity from it.
The Lancer: Jesus left Peter in charge of the movement he started. According to the Catholic Church, the whole "I'm giving you the keys to my kingdom" scene represents Peter becoming the first pope.
Actually, he may be more of a Big Guy if you want to do the Five Man Band.
Living Lie Detector: One incident in Acts has a guy named Ananias attempting to commit fraud, but Peter sees right through the con. Ananias dies on the spot. A few hours later, Ananias's wife, Sapphira, tried to do the same and suffered the same fate.
One Steve Limit: Enforced. Since there was another Simon among the twelve, Jesus gave him the Peter nickname instead.
Red Oni, Blue Oni: Initially, Peter was the hot blooded foil to Jesus's calm demeanor, but post-Pentecost, he got better and became Paul's foil.
Paul (Saul) of Tarsus
"Saul, Saul, why persecute thou me?"
The Atoner: When he had an epiphany on the road after witnessing Stephen's stoning, which inspired him to spread Christ's teachings.
Badass: Fighting wild beasts in Ephesus; being stoned, dragged out of the city, and left for dead only for his followers to find him very much alive later on.
Self Restraint: Was once in jail with Silas when the wall miraculously collapsed - they stayed put.
Spell My Name Without An S: Saul is Paul's Hebrew name. Due to having dual citizenship (Jewish and Greco-Roman), Saul/Paul has two names. Since Paul is mostly shown in Greco-Roman territory, he goes by Paul.
Unwanted False Faith: Acts 14, Paul and Barnabus are witnessing in one Greek city and performing some miracles while they were at it. The citizens of the city were convinced that they were the Gods, Hermes and Zeus respectively and set up a whole procession to sacrificing to them as such. The apostles had to go to considerable lengths trying to make them to stop. This, in turn, made it easier for troublemakers to convince the very same citizens to attempt stoning Paul and Barnabus to death.
"Woe to you Pharisees, because you give God a tenth of your mint, rue and all other kinds of garden herbs, but you neglect justice and the love of God. You should have practiced the latter without leaving the former undone."
Dramatically Missing The Point: See quote. They followed the ceremonies of the law to a T, but (the Christians argued) they completely over looked the more important spirit of the law.
God Never Said That: God gave a number of general rules, but by Jesus' time these had been analyzed and quantified into strict rules by the Pharisees. When the Pharisees tried to call Jesus on his "rulebreaking", He often explained that they had over analyzed the letter of the law and missed the spirit completely. For example, the Pharisees said He violated the Sabbath's ban on work by healing someone; He explained that while the Sabbath is a day of rest it's never against God's law to help a person or show mercy on them (See Matthew 12).
Evil Cannot Comprehend Good: "If you had known what these words mean, 'I desire mercy, not sacrifice,' you would not have condemned the innocent."
Hypocrite: Their religion was more to make then look good in front of men then out of any real love for God. For example, they got mad at the disciples for eating with unwashed hands, but they themselves plotted murder and stole from people.
Token Good Teammate: Gamaliel, who spoke out in the defense of the apostles when they were first arrested. His argument was to let them go, because many false teachers had come and gone and likewise the apostles would do the same. But if their words turned out to be truthful, he said, then the Pharisees would only be fighting a futile battle against God. Gamaliel was also said to be the teacher of Paul.
Well-Intentioned Extremist: They will often do the worst things to protect their community. Remember that last time Israel strayed from God's commands their kingdom was destroyed and their people scattered, so of course they don't take kindly to Christianity.