All I ever need is you can be expressed in various ways using different synonyms. Some options could include, "you're my everything," "you complete me," "my heart belongs to you," "you're essential to my being," "I cannot live without you," or "you are the missing piece to my puzzle." These synonyms all convey the same sentiment of complete and utter devotion to the person who is the subject of the statement. Whether spoken or written, these phrases demonstrate a deep love and need for the other person's presence and companionship. They emphasize the importance of that special bond and the irreplaceable role that person plays in one's life.