If I were forced to make a top 100, it would look something like this, limiting myself to max. 2 films per director:

1. Ballet Mécanique (Léger, 1924)
2. Der Letzte mann (Murnau, 1924)
3. La Passion de Jeanne d’Arc (Dreyer, 1928)
4. Chelovek S Kinoapparatom (Vertov, 1929)
5. Top Hat (Sandrich, 1935)
6. You Can’t Take it with You (Capra, 1938)
7. Bringing Up Baby (Hawks, 1938)
8. The Maltese Falcon (Huston, 1941)
9. Citizen Kane (Welles, 1941)
10. To Be or not to Be (Lubitsch, 1942)
11. Sullivan's Travels (Sturges, 1942)
12. Cat People (Tourneur, 1942)
13. Meshes of the Afternoon (Deren, 1943)
14. The Life and Death of Colonel Blimp (Powell & Pressburger, 1943)
15. At Land (Deren, 1944)
16. The Lost Weekend (Wilder, 1945)
17. Fireworks (Anger, 1947)
18. Letter from an Unknown Woman (Ophüls, 1948)
19. A Letter to Three Wives (Mankiewicz, 1949)
20. Un chant d'amour (Genet, 1950)
21. Singin' in the Rain (Donen & Kelly, 1952)
22. The Band Wagon (Minnelli, 1953)
23. Viaggio in Italia (Rossellini, 1954)
24. This Island Earth (Newman, 1955)
25. The Night of the Hunter (Laughton, 1955)
26. Ordet (Dreyer, 1955)
27. Written on the Wind (Sirk, 1956)
28. Bigger than Life (N. Ray, 1956)
29. Vertigo (Hitchcock, 1958)
30. Anatomy of a Murder (Preminger, 1959)
31. The Apartment (Wilder, 1960)
32. Psycho (Hitchcock, 1960)
33. Days of Wine and Roses (Edwards, 1962)
34. Dog Star Man (Brakhage, 1962-1964)
35. La Ragazza che sapeva troppo (Bava, 1963)
36. All that Heaven Allows (Sirk, 1963)
37. Blood Feast (Lewis, 1963)
38. Otto e Mezzo (Fellini, 1963)
39. Le Mepris (Godard, 1963)
40. Spider Baby (Hill, 1964)
41. Il Deserto Rosso (Antonioni, 1964)
42. Obchod na Korze (Kadár & Klos, 1965)
43. Cat on a Hot Tin Roof (Brooks, 1965)
44. Kustom Kar Kommandos (Anger, 1965)
45. La Battaglia di Algeri (Pontecorvo, 1966)
46. Persona (Bergman, 1966)
47. Who´s Afraid of Virginia Woolf (Nichols, 1966)
48. Point Blank (Boorman, 1967)
49. Playtime (Tati, 1967)
50. Take Me (Dwoskin, 1968)
51. C'era una volta il West (Leone, 1968)
52. 2001: a Space Odyssey (Kubrick, 1968)
53. Anamnesis (Zwartjes, 1969)
54. Il Conformista (Bertolucci, 1970)
55. Beyond the Valley of the Dolls (Meyer, 1970)
56. Pink Flamingos (Waters, 1972)
57. Le Charme discret de la bourgeoisie (Buñuel, 1972)
58. Don’t Look Now (Roeg, 1973)
59. Double Agent 73 (Wishman, 1974)
60. The Conversation (Coppola, 1974)
61. A Woman Under the Influence (Cassavetes, 1974)
62. Picnic at Hanging Rock (Weir, 1975)
63. Zerkalo (Tarkovsky, 1975)
64. Barry Lyndon (Kubrick, 1975)
65. The Rocky Horror Picture Show (Sharman, 1975)
66. Profondo Rosso (Argento, 1975)
67. Taxi Driver (Scorsese, 1976)
68. 3 Women (Altman, 1977)
69. In Einem Jahr mit 13 Monden (Fassbinder, 1978)
70. Creation (Brakhage, 1979)
71. Stalker (Tarkovsky, 1979)
72. Fanny och Alexander (Bergman, 1982)
73. Koyaanisqatsi (Reggio, 1983)
74. Videodrome (Cronenberg, 1983)
75. The Times of Harvey Milk (Epstein, 1984)
76. Love Streams (Cassavetes, 1984)
77. Re-Animator (Gordon, 1985)
78. Shoah (Lanzmann, 1985)
79. Brazil (Gilliam, 1985)
80. Blue Velvet (Lynch, 1986)
81. Der Himmel über Berlin (Wenders, 1987)
82. Au Revoir les Enfants (Malle, 1987)
83. Withnail and I (Robinson, 1987)
84. The Thin Blue Line (Morris, 1988)
85. Do the Right Thing (Lee, 1989)
86. Braindead (Jackson, 1992)
87. Short Cuts (Altman, 1993)
88. Dazed and Confused (Linklater, 1993)
89. Satantango (Tarr, 1994)
90. Ta'm e guilass (Kiarostami, 1997)
91. Cheun gwong tsa sit (Wong, 1997)
92. Outer Space (Tscherkassky, 1999)
93. Éloge de l'amour (Godard, 2001)
94. Moulin Rouge (Luhrmann, 2001)
95. Cremaster 3 (Barney, 2002)
96. La Mala educación (Almodóvar, 2004)
97. Princess Raccoon (Suzuki, 2005)
98. A History of Violence (Cronenberg, 2005)
99. The New World (Malick, 2005)
100. INLAND EMPIRE (Lynch, 2006)