To name a bed in a box mattress, the best is quite hard since many serve different purposes. But if I were to recommend a bed in a box, it would have to be the Silk Symphony by BEDINABOX as it has two layers of varying degrees of softness. The Silk Symphony mattress can be flip over for two different firmness levels and hence, you're essentially getting two mattresses for the price of one. But if your budget isn't big, it's best to settle for something else. Visit this website to know more about the best mattress.