They are a great source of amino acids, carbohydrates, vitamins and barely any fat! Yes, you read that part right, potatoes are much more nutritious than most people think.
As a matter of fact, you can live eating potatoes almost exclusively (as the main ingredient for many of your meals) and be completely healthy, of course, you can eat other stuff if you want.
To be honest, potatoes are an essential part of my daily meals, and they can be part of yours as well.