William for a boy! (Shakespeare, Blake, Wordsworth, Godwin, Yeats, Golding, Somerset Maugham, Faulkner, Wharton etc - loads of the most prominent/classic male writers seem to have been called William as well as it being used for characters from Shakespeare, Austen, Bronte, Dickens, Tennyson...
). Mary/Maria or maybe Jane would probably be the girls equivalent.
But I'm guessing you mean names that instantly make you think "literary character" because they are relatively uncommon or invented by the writer - so Atticus, Lysander, Orlando, Caspian, Holden, Lyra, Coraline, Miranda, Perdita, Cordelia, Ophelia are some of my fave more obvious character names (even if I don't always like the characters themselves).