The Winning Trial Advocacy Tips blog has a great post titled "Sources for Closing Argument Stories." The post identifies nine different sources for stories that can be used in closing arguments.
Here is brief excerpt:
1. Aesop’s Fables. Aesop’s Fables contains dozens of valuable themes for use in your next trial. By weaving these fables into your closing argument, you’ll help jurors immediately understand the underlying values of your arguments and see why your client deserves to win. The Tale of the Sour Grapes, the Tale of the Lioness and the Vixen, the Tale of the Wolf in Sheep’s Clothing — these stories will not only educate your jurors, they’ll also entertain them.