When referring to someone or something of importance or superiority, there are a variety of synonyms for the phrase "number one". Some commonly used phrases include "top dog", "champion", "kingpin", "leader of the pack", and "top performer". Other synonyms include "the best", "the cream of the crop", "the elite", and "the top-notch". Using creative synonyms can add interest and depth to your writing, while still conveying the same core meaning as "number one". Whether you're describing a sports team, a business leader, or a celebrity, there are plenty of synonyms to choose from to capture their excellence and importance.