You can demonstrate that you are not just another pretty transcript by showing a completely different side of yourself through the role models and influences that shaped the person you are today. The key here is to personalize: Do not go off on tangents, focusing on someone else instead of the most important element—why your topic is significant to you. Focus on what these influences have meant to you and how you have grown, tying in relevant aspects of your personal or family life when appropriate. Show your strengths in new ways without restating the obvious.
However, do not feel that you need to write about famous people or impress admissions officers by noting your family's ties to an influential member of the government or movie star. Writing about a teacher who sparked your interest in archeology by taking your third-grade class on a field trip to a local museum to see a dinosaur exhibit is more effective than name dropping in the hopes of impressing admissions officers.
If you can demonstrate unusual maturity, sensitivity, and direction in your essay, you will be ahead of the game.