The antonyms for the word "un-happiest" are many. For starters, the opposite of being unhappy is being happy. So, the antonym for the word "un-happiest" would simply be "happiest." Other antonyms for the word include "joyful," "pleased," "content," "satisfied," and "cheerful." Each word represents a different level of happiness, from being simply content with life to having a profound sense of joy and fulfillment. Whatever the antonym, the opposite of being unhappy is something to strive for in life, as it represents a state of mind that brings peace and contentment.