Who was the most famous of the sons of Jacob?

Joseph.

1) It was thanks to him that Jacob and his family survived the famine (Genesis ch.46 and ch.50).
2) He was the only person from the time of Jacob until Moses who experienced prophecy in any form. (Joseph had prophetic dreams. Genesis ch.37.)

3) Joseph was viceroy in Egypt (Genesis ch.41); and it was thanks to him that the nation of Egypt survived the famine.

4) During the long sojourn of the Israelites in Egypt, Joseph took steps to preclude them from assimilating (Genesis 46:31-34).

5) Jacob considered Joseph the most worthy of his sons (Genesis 37:3 and 49:26); and he was deemed important enough to comprise two of the twelve Israelite tribes (Genesis 48:3-5).

6) He was the ancestor of Joshua (1 Chronicles ch.7).

7) Joseph was steadfast in withstanding temptation (Genesis ch.39).

See also:

God's providence for Joseph

Jacob and Joseph

Jewish history timeline