Which is the best skin care product?

We tend to segregate people into 4 groups based on their skin types i.e. dry skin, oily skin, normal skin and sensitive skin. However, this classification is just too broad to be used definitively in determining the best skin care product. We can say best skin care product for a dry skin or best skin care product for an oily skin are better statements than just best skin care product. But really, that is what it is better; still not accurate.