The LA Times wrote a good article about what it takes to reach a 5 Star rating with Forbes Travel. According to the LA Times:
It may not come as a surprise that California — a sun-splashed magnet for celebrities and big-spending tourists — leads the nation with the number of hotels winning five-star ratings from Forbes Travel Guide. But winning the coveted rating is no easy feat. Only 58 hotels in the U.S. — 12 in California — were awarded the recognition this year, including, for the first time, the Resort at Pelican Hill in Newport Beach.
The Forbes five-star rating is considered more difficult to land than the five-diamond rating from AAA, which awarded its top ranking to 101 hotels in the U.S. this year.
Hotel owners vie for the Forbes distinction because it enables them to charge much higher rates. For example, the four-star Beverly Hilton recently posted average daily rates of $245 to $325, while the five-star rated Beverly Hills Hotel posted rates of $510 to $540.
The main difference between a 4-star hotel and a 5-star hotel is typically guest service and amenities. From the article:
It may not come as a surprise that California — a sun-splashed magnet for celebrities and big-spending tourists — leads the nation with the number of hotels winning five-star ratings from Forbes Travel Guide. But winning the coveted rating is no easy feat. Only 58 hotels in the U.S. — 12 in California — were awarded the recognition this year, including, for the first time, the Resort at Pelican Hill in Newport Beach.
Marriott plans to add 150 franchised MOXY HOTELS in Europe over the next 10 years, aiming for locations in Germany, Austria, United Kingdom, Ireland, Belgium, Italy, The Netherlands, Denmark, Finland, Norway, and Sweden. The new brand will fuel Marriott’s company-wide growth in the region, which is expected to reach 80,000 rooms by 2015.
Forbes Travel (formerly Mobil) has just released its list of hotels that achieved their top rating for 2013. Forbes rates hotels in a similar manner as AAA but uses stars instead of diamonds. Both use a scale of 1 to 5. Forbes added quite a few more properties to their list for 2013. From the press release:

The path to a Five Diamond Rating is rigorous. Properties identified by AAA as potential candidates for the Five Diamond Rating undergo multiple unannounced evaluations by a AAA inspector and final decision by a panel of experts. In addition to the evaluation of physical attributes, potential Five Diamond establishments are subject to thorough onsite assessments of all guest services from the initial reservation through checkout for hotels and from seating to presentation for restaurants. Each area is evaluated based on level of competence, refinement and hospitality.
Never say: “My credit card declined? That’s impossible. Run it again.”