By the end of the movie, Harry is not only at peace with her annoying habit, he lists it as one of the things he loves about her.
Johnny Depp's Jack Sparrow is rife with quirks. He twitches, he sways, he mumbles riddles nobody can understand. He's unabashedly selfish and sneaky. Depp's portrayal of Willy Wonka is similar, with a whole other package of quirks/weirdnesses to keep us interested.
Charles Dickens grew to popularity on the backs of his quirky characters like Nurse Ratchet, Miss Havisham, Scrooge. Sheridan's Mrs. Malaprop misused words so frequently that doing so is now called a 'malapropism'. LM Montgomery gave Anne Shirley the deep desire to trade her red hair for black. Dobby the elf likes to wear tea cozies as hats.
If we create them right, our characters should have lots of quirks. These habits/behaviors make them unique, help us to identify with them, give us handles to keep them straight in our minds. I admit - I'm not a quirky person so remembering to add this into my character brew is something I struggle to do.
What are some quirks you've added to your characters?