One of my favorite restaurant rating systems is from the book "Blue Highway", by William Least Heat Moon. He makes a cross country voyage of discovery in the mid 70s, sleeping in his van. He talks about his method of rating cafes and diners by the number of advertising calenders on the wall. Two or three calenders are OK, four or five is very good, and somewhere out there is the whispered about, but never seen seven calender Holy Grail of diners. This is a great read, written before the chain stores and restaurants took over small town America. The title Blue Highway represents the color of the two lane roads on the map, which he travels on almost exclusively.