Although I take Consumer Reports with a grain of salt it seems readers of Consumer Reports have rated The Paleo Diet 2nd overall.

The diets looked at were:

Commercial Plans - Weight Watchers (74), Medifast (70), Jenny Craig (66), Nutrisystem, (56)

DIY Plans- Myfitnesspal (83), Paleo Diet (80), Mediterranean Diet (77), SparkPeople (76), South Beach Diet (72), Grlycemic Index Diet (71), Low-carb diet (other than Atkins) (71), Atkins Diet (70), Slim Fast (60)

The criteria were Initial Weight Loss, Maintenance, Calorie Awareness, Food Variety, Fruits and Veg, Exercise. Where Paleo really failed compared to Myfitnesspal was calorie awareness. In my mind that is one of the strengths of Paleo, no tracking just eat.