The term "most small fry" implies something or someone that is insignificant or unimportant. The antonym for this expression would be "most significant" or "most important." To be viewed as significant, one must have weight, power, merit, or relevance. Examples of the antonyms of small fry include "major player," "significant player," "heavy hitter," "big-time player," "powerhouse," or "heavyweight." These are terms used to describe individuals or events that carry great importance or influence. In summary, while "most small fry" suggests insignificance, "most significant" or its synonyms imply importance, power, and influence.