The term "most dime-a-dozen" refers to something that is unoriginal, commonplace, and unspecial. Its antonyms include words like rare, unique, exceptional, extraordinary, and unparalleled. These words denote something that is unlike anything else, something that stands out and is worth noticing. These antonyms are often used to describe collectibles, works of art, people, or experiences that are truly remarkable and one-of-a-kind. They connote a level of quality and distinction that sets them apart from the ordinary and makes them valuable. So, when you want to describe something that is not ordinary, steer clear of "most dime-a-dozen" and use its antonyms instead.