Aunt Abby & Aunt Martha Brewster
(in Arsenic and Old Lace by Frank Capra)
At the center of Capra’s madcap classic are two of the sweetest little old ladies you’re likely to find anywhere this side of your grandmother. In fact, they’re so sweet viewers would be likely to pass them off as maudlin clichés—were it not for their unforgettable desire to help lonely old men… by poisoning them.
Wonderful examples in this post -- shading your characters will make them memorable.