It is my considered opinion that you should go to The Elephant House on Chamber Street in Edinburgh for 4 reasons.
1. The decor. There are Elephants! All over. Who doesn't like elephants? Little ones, big ones, posters, chairs, wooden and ceramic elephants.
2. The food's good. I recommend the tea and the stromboli. Maybe not together, you understand...but still.
3. If you read or heard about this book series called Harry Potter than you might be interested in seeing the place. Since it's 'the birthplace of Harry Potter.' It says so on the window. They even sell postcards of J.K. Rowling working in the back.
4. Because the graffiti in the bathrooms is about as unique as it is possible to be. My apologies for the fuzzy shot. I figure you can get the gist of it. That's only one small part of one stall in the ladies room.