Here's one I don't think I have seen yet.  An interesting topic that has probably rattled through everyone's mind at least once.  So I'll get the ball rolling, and feel free to voice your displeasure.
1. Stanley Kubrick
2. Martin Scorsese
3. David Lean
4. Elia Kazan
5. Ingmar Bergman
6. Luis Bunuel
7. Jean Luc Godard
8. Federico Fellini
9. Woody Allen
10. Buster Keaton

I also realize that Hitchcock, Renoir, Kurosawa, Ford, Hawks, Ray, and many others aren't on here, but I can only fit ten.