I love comparing Ariel with Caliban. They have similar goals (getting their freedom), but they go about their goals in very different ways. Ariel works with Prospero, does his best at his job, and tries to win his freedom without cheating his master. This loyalty comes from the fact that Prospero freed him from a tree, in which he had been trapped by the witch who once inhabited the island. Caliban feels no loyalty to Prospero, and so he works against him, plotting his death.
The song I Want To Break Free, by Queen, makes me think of Caliban and Ariel, because it shows their desires.