As of 2011, the most famous Sephardi rabbi in Israel is former Sephardi Chief Rabbi of Israel, Rabbi Ovadia Yosef.
I would say NO, he isn't the most famous Rabbi, but definitely one of the more known ones in the last two centuries (he died in 1810).
The Chief Rabbi is in charge of the Jewish community in the country he lives in.
There are a lot of famous rabbis, many are regional though.
Shimon sofer was was a famous a rabbi and a member of parliament
Mordecai, in the Book of Esther.
most likely the RomBom (Rabbi Moshe ben Maimon) otherwise known as maimonidies there was a rabbi after him also in Spain called the RomBon (Rabbi Moshe ben Nachmun) or Nachmonidies, he was pretty famous too
Rabban (Rabbi) Yochanan ben Zakkai (1st century CE) lived his entire life in the Holy Land, in Jerusalem, and later in a town called B'ror Chail (in his last years). His chief disciples were Rabbi Eliezer and Rabbi Yehoshua, the teachers of Rabbi Akiva. Rabbi Eliezer settled in Lod, while Rabbi Yehoshua lived in Pekiin. Rabbi Yochanan ben Zakkai was also famous for creating the Yeshivah at Yavneh (Talmud, Gittin 56b).
No His father was just a rabbi and his other was a stay at home mom
Rabbi Yochanan ben Zakkai, Rabbi Yonatan ben Uziel, Chanina ben Dosa, Bava ben Buta, Shimon ben Hillel, Rabbi Eliezer, Rabbi Gam'liel, Rabbi Yehoshua, Rabbi Akiva, Rabbi Nechuniah, Rabbi Nachum Gamzu, Rabbi Yossi Glili, Rabbi Honi Me'agel, Rabbi Abba Shaul, and hundreds of others. Each of these had large groups of disciples.See also:More about the PhariseesJewish history timeline
Japan is a famous country!!!
Judaism is not a centralised religion with a single head. Although some countries have a head rabbi for that country, in most places different communities have their own head rabbi. Often, a single city with a large Jewish population will have a different head rabbi for different groups. Israel has two head rabbis, one Ashkenazi and the other Sephardi, for example.