The Charge of the Goddess is Doreen Valiente's masterpiece, incontestably the best of its kind.
In fact, the Charge has single-handedly created its own literary genre. Modern paganism's hodgepodge of gods, few of whom many of us grew up knowing about, has made the charge—a "self-description of a deity"—a liturgical necessity.
Note that the pagan use of the term, though, departs significantly from its original use in Freemasonry, where it means, essentially, "a list of instructions." Although the divine monologue was known in late antiquity—Classicist R. E. Witt would call it an "aretalogy"—Valiente's Charge is the Great Mother of all modern charges.
Think of the other charges that you know.