1. Martin Scorsese
2. Ridley Scott
3. Christopher Nolan
4. Steven Spielberg
5. Orson Welles
6. Sergio Leone
7. Quentin Tarantino
8. Edgar Wright
9. Alfred Hitchcock
10. Tim Burton
11. Frank Darabont
12. Akira Kurosawa
13. Danny Boyle
14. David Lynch
15. The Cohen Brothers
16. Stanley Kubrick
17. The Wachowski brothers
18. Hayao Miyazaki
19. Francis Ford Coppola
20. Cecil B. Demille
21. Carl Theodor Dreyer, Jr.
22. Terrence Malick
23. George Cukor
24. Paul Thomas Anderson
25. Lars von Trier
26. James Cameron
27. Ang Lee
28. Frank Capra
29. David Cronenberg
30. Darren Aronofsky
31. Guy Ritchie
32. M Night Shyamalan
33. Kathryn Bigelow
34. Chan Wook-Park
35. Kevin Smith
36. Clint Eastwood
37. Oliver Stone
38. Roman Polanski
39. Spike Jonze
40. Lisa Cholodenko
41. John Hughes
42. Jean-Pierre Jeunet
43. Guillermo del Toro

This is less at your request Jean, and more being shocked that his name hasn't already been added to this list already. And you're right, there is an American bias, because people are going with what they know. So far, I've mostly added British directors because very few other people have, and there's a few directors I've seen that continually impresses me. If there's a Russian or any other "foreign" director you feel is one of the greatest directors of all time, add him or her to the list, whether people have heard of them or not. On the plus side, even if people haven't heard of them, it'll at least direct attention to them!