One of the most charming things in astronomy, IMO, is the theme naming of planetary features.
The craters of Mercury, which is named after the Roman god of messages and information (among other stuff), bear the names of artists: composers (Haydn, Verdi, Vivaldi), writers (Homer, Vyasa, Murasaki), and painters (Giotto, Harunobu, Goya).
Large features of Venus are named after women of myth: mountains and plateaux after goddesses (Freyja, Tefnut, Lakshmi, Aphrodite), plains after mortals (Guinevere, Leda, Lavinia). Smaller features are named after women of history: scientists like Lise Meitner, artists like Anna Pavlova, and rulers like Cleopatra.
Having been named first, the features of our Moon and Mars are a bit all over the place.
The lunar maria ("seas") are named after states of mind: Tranquility, Serenity, Ingenuity, and, uh, Moscow. Or after clouds (Mare Imbrium) and storms (Oceanus Procellarum). Craters bear the name of astronomers (Tycho, Hipparchus), physicists (Oppenheimer, Leibnitz), and space travellers (Grissom, Gagarin), but there's a bit of everything (Caesar, Icarus).
On Mars, we have the plains of silver (Argyre) and gold (Chryse), the Tharsis plateau, plains named after Greece, Isis, and Utopia, mount Olympus and mount Peacock, and more astronomers for the craters (Huygens, Herschel, Lowell). The moons of Mars are of course named after the sons of the god of war, Deimos ("dread") and Phobos ("panic").
Jupiter doesn't have many permanent surface features, of course, but its moons are named after Zeus' numerous lovers: Io, Europa, Callisto, the boy Ganymede, Metis, Leda, Pasiphae. One exception is Amalthea -- the goat that nursed him as an infant on Crete. The features of volcanic Io are mostly named after fiery, temperamental gods (Loki, Chaac, Amirani); those of Europa after places from Europa's own legend (Cyclades, Tyre) or Celtic myth (Conamara, Annwn, Dyfed); those of Callisto after Nordic myth (Valhalla, Asgard, Fimbulthul); those of Ganymede after Egyptian holy cities (Memphis, Abydos) and Mesopotamian myth (Mummu, Lakhmu).
The moons of Saturn are named after Titans, the brothers and sisters of old Chronos: Rhea, Dione, Tethys, Enceladus, Prometheus, Pandora, Iapetus, and of course the largest is just named Titan. The largest features of Titan bear the name of all orts of places of legend (Dilmun, Xanadu, Aztlan, Shangri-La), its creaters of deities of wisdom (Papuan Afekan, Etruscan Menrva, Lakota Ksa), and its hills after JRR Tolkien's characters (Bilbo, Gandalf, Arwen).
The moons of Uranus are all named after characters from Shakespeare's plays (Oberon, Titania, Puck, Miranda, Caliban, Cordelia) and Alexander Pope's poems (Ariel, Umbriel). Shakespearian names are also given to the craters of Oberon (Coriolanus, Falstaff, Romeo) and Titania (Calphurnia, Jessica, Imogen).
The moons of Neptune are of course all water deities and creatures: Triton, Naiad, Thalassa, Proteus, Hippocampus. The features of Triton are named after monsters of the deep sea (Kraken, Apep) or water-related deities and spirits (Heqet, Hiruko, Tangaroa).