The phrase "highest rating" refers to a very positive evaluation or assessment, often given by an expert or authority in a particular field. It indicates that something has been judged as being exceptional or outstanding when compared to others of its kind, and is therefore considered the best possible option among many alternatives. The term can be used in various contexts such as movies, TV shows, books, products, services, etc., where a critic or reviewer assigns a score or grade based on specific criteria, and the highest rating signifies that it has met or exceeded all expectations.