(poster #3 and I posted simultaneously)
While there are many authors who have, indeed, created such memorable characters that one only need mention the name of the character and an image comes to mind, there are few that have immortalized so many as has Dickens.
Shakespeare is, perhaps, his only competition as he has certainly immortalized many a character, fictional, or real, Such characters as Hamlet, Macbeth, Romeo and Juliet, Lear, Othello, Shylock, Portia, Puck are all names that represent for readers archetypes.
The renowned critic, Harold Bloom, mentions in his book, Shakespeare: The Invention of the Human:
...his principal characters have become our mythology....
For instance, Bloom, who himself is Jewish, also notes that Shylock has done more than any other character to stereotype the usurer as a cruel, heartless and obsessively greedy Jew [at least before news of Bernie Madoff]. Hamlet epitomizes the melancholic; in fact, Bloom contends, he instructed Freud, Shakespeare's "involuntary follower." And, so on.