1. Both novels are categorized in Dickens' orphan series. Pip from Great Expectations and David are children who have lost one or both parents and who experience abuse at the hands of someone who is raising them (Pip from his older sister and David from his stepdad).
2. Like most of Dickens' books, each work contains its share of whimsical, lighthearted characters who help the protagonists on their journeys through life. In Great Expectations, Pip rooms with Herbert Pockett and begins to take advice from Mr. Wemmick. Both characters are unique and very optimistic. They eventually cause Pip to realize what is important in life. Similarly, David fortunately meets the Micawbers, a rather eccentric couple who take in David during his dark hours and who prove to be loyal friends.
3. Each novel possesses a villain(s). Pip struggles against Orlick (his sister's attacker) through much of the novel and must compete with the abusive Drummle for Estella's love. David faces Uriah Heep in his struggle to make it through life and work and endures the death of his dear friend Em'ly because of the selfish Steerforth.
4. Finally, these two Dickens works are Bildungsroman--literary works which trace the maturation of (or building up of) the main character (Harper Lee's To Kill a Mockingbird is a good example of this type of novel).
Of course, readers can also make many comparisons between these works' style, diction, and characterization because Dickens' novels follow very specific patterns (see also Nicolas Nickleby and Oliver Twist).