Yudel Krinsky is number one according to Newsweek because:
As the leader of the Chabad-Lubavitch movement, Krinsky is the contemporary face of the Hasidic branch.
Note there is nothing Krinsky has done that is mentioned as special, wise or unusual.
What this really means is that Krinsky is number one because in Newsweek's estimation, Chabad is now the most important branch of Judaism in America. He isn't special; Chabad is.
Morris Allen—As program director for Magen Tzedek, the ethical kosher seal, Allen is changing the way the world thinks about kashrut and the ethical issues surrounding the hechsher.
Sara Hurwitz—Hurwitz rose to national attention when Rabbi Avi Weiss (No. 18) bestowed her with the title of “rabba.” She is considered the first Orthodox woman rabbi ordained in the United States, and in this role she has had an impact on the roles considered acceptable for modern Orthodox women.
Mark Dratch—As founder of JSafe (The Jewish Institute Supporting an Abuse-Free Environment), Dratch is a nationally recognized speaker and consultant in matters of domestic violence, child abuse, and professional abuse within the Jewish community.