preeminent
Clearly the best or most important among all others.
Preeminent means standing above everyone else in importance, skill, or achievement. When someone is the preeminent expert in a field, they are widely seen as having unmatched knowledge and accomplishments. A preeminent scientist might be the world's leading authority on black holes, the person other researchers turn to when they need answers.
The word carries a sense of clear superiority that many people recognize. You might be the best player on your soccer team, but the preeminent soccer player in the world is someone like Pelé or Messi, whose excellence is widely admired.
Preeminent often describes people who have achieved lasting recognition: preeminent artists, preeminent historians, preeminent musicians. When Marie Curie became a preeminent researcher in radioactivity, she didn't just know more than others, she helped define the entire field.