The antonyms for "haddest go at" are many, depending on the context in which the phrase is used. If the phrase is used in the context of trying something new or attempting to do something, then the antonyms could be "avoided," "neglected," or "ignored." If used in a competitive context, the antonyms could be "surrendered," "conceded," or "yielded."
Moreover, in a workplace or educational setting, the antonyms could be "procrastinated," "postponed," or "delayed." If the phrase is used in a social context or trying to make a connection. The antonyms could be "ignored," "disregarded," or "overlooked.