Firm mattresses have the least amount of padding and foams on the surface which provides a firmer feel. If you have no problem sleeping comfortably on your living room floor, and don't wake up with aches and pains, a mattress with a firm comfort level would be the ideal choice for you. Firm mattresses show less of a body impression over time because less comfort materials are used in the top layer.
Plush mattresses offer a medium overall feel but provide a softer surface comfort than the firm level. Mattresses in this category are great if you are seeking comfort that's not too hard and not too soft. Plush comfort is also a perfect choice for two people that don't agree on a comfort level.
Pillow Top mattresses are generally the softess option and have an extra layer of comfort materials that consists of padding and foams. If you find yourself using a feather bed or are looking for that cloud like feel, pillowtops are the right level for you. They will cradle and support your every move with pillow like softness while you sleep.