Atlantic City has some of the only free beaches in South Jersey. The beaches are fairly wide and are separated from the boardwalk by sand dunes. Activities and entertainment are more adult oriented since you need to be over 21 to gamble in the casinos. Visitors come from a wide variety of countries making it very multi-lingual.
Ocean City charges a fee to go on to the beach. The beaches are narrow but clean. The town is well suited for families with young children. Adults may find it a bit unusual that it is a "dry" town.
Wildwood has wide beaches. From the boardwalk, you can look out across the beach and see the ocean. The town is best suited for teenagers with plenty of amusements, games of chance and other teenagers on parade.