This is called secondary meaning or acquired distinctiveness. The other types of non-inherently distinctive marks that require secondary meaning are geographic and personal name marks. Marks that are inherently distinctive do not require proof of secondary meaning to obtain federal registration. Arbitrary and coined marks are inherently distinctive. A coined mark is one that has been invented to function solely as a trademark or a word that is completely out of common usage and totally unfamiliar to the ordinary consumer.
Suggestive marks are also inherently distinctive.
But there is often a fine line between suggestive and descriptive marks and such determination can be rather subjective. Suggestive marks merely suggest a quality or ingredient of the goods. You obviously want to stay away from generic and non-inherently distinctive marks. While coined marks can be very strong, you may have to invest more effort in the promotion of the coined mark. It is the author's opinion that some of the best marks border between suggestive and arbitrary or coined.