Well, there is no definitive answer to this. It seems more like a matter of personal choice. However, greasy creams are surely less popular as compared to the non-greasy (or less greasy) ones. Since the application of skin care creams is easier, they seem to be preferred (over lotions) in cases where the skin care product is not to be removed immediately after application. So, skin care creams seem more popular as moisturisers than as cleansers or toners. For toners, lotions seem to be preferred over skin care creams. There are some skin care creams that acts as toners too, but generally the toners are available in liquid form only. For cleansing, lotions and skin care creams are equally popular; however, the tilt seems more towards lotions.
Creams are known to be most effective in keeping skin moist; hence, the most popular form of skin care creams is moisturisers. Due to the same reason, a lot of people tend to associate skin care creams with dry and sensitive skin. Though it is true to a certain extent, skin care creams are not used only for dry skin, they are also used for making products for oily skin e.g. vitamin A creams and sulphur creams that help reduce the rate of sebum production.
Skin care creams are also used for products that cater to skin disorders especially for disorders that require the application of product over a small localised area. This is again due to the fact that skin care creams are easier to apply (without wastage) on the affected area. However, in cases where skin needs to be washed using a medicine/product, lotion is a better choice. Mostly, the manufacturers too realize this fact, making it easier for you to choose between a lotion and a skin care cream
Eye-creams and anti-ageing creams are other examples where skin care cream is preferred over its lotion counterpart.
Whatever your choice be (cream or lotion), knowing how to use it effectively, is more important than anything else.