Usually the category that your dog fits into will be the best option. Eg small, medium, large and age specific.
With dog food, you tend to get what you pay for. I tend to recommend premium dog food that is suited to the age and health requirements of the individual. There are many brands on the market that offer a variety of flavours, calories and ingredients. If you want to reduce plaque ask you vet about dental dry foods. Dry food is usually best but premium quality wet food can provide variety and may tempt fussy palates.