When it comes to finding synonyms for the word "fussiest," there are a few different options to consider. Some possible synonyms might include "picky," "finicky," "demanding," "choosy," or "selective." These words all suggest someone who is very particular or specific about certain things, perhaps even to the point of being difficult or hard to please. Other possible synonyms could include "fastidious," "meticulous," or "perfectionist," which suggest a focus on details and a desire for everything to be just right. Overall, there are many different words that could be used as synonyms for "fussiest," depending on the specific context and meaning.