I am so curious about what you are thinking right now. What do you consider the greatest love story? There are certainly some famous stories out there: Romeo and Juliet, Beauty and the Beast, Sense & Sensibility or Pride and Prejudice. (Jane Austen seems to have a monopoly on great love stories!)
As The Heart Whisperer, I certainly hear many love stories. Some of them are tragedies. Some of them are more like fairy tales, but most of them fall in a category somewhere in between.