The most successful Jewish director of all time...
Alright, that's a tall order. How do you define "successful", anyway? Probably have to go with Billy Wilder or Steven Spielberg, right?
Unless you count success by Oscar nominations and wins. Then the answer is not Wilder (eight and two) or Spielberg (seven and two, "Shakespeare in Love" be damned), it's William Wyler. With a whopping 12 nominations and three wins, Wyler is the only director in history to helm three Best Picture winners. (The only one to beat him with four director statues, the goyishe John Ford, can only claim one best picture.)
So what movies did Wyler win for? Honestly, we don't know much about "Mrs. Miniver" (1942), or "The Best Years of Our Lives" (1946), but we definitely have heard of "Ben-Hur" (1959).
Errr... Ben-Hur? The most successful JEWish director of all time is Steven Spielberg. Period.