I’ve only watched a few before and those were a long time ago. I am going to enjoy going through the list

20. Citizen Kane
19. A Man Escaped
18. Sweet Smell of Success
17. Notorious
16. Godfather 1 & 2
15. To Have and To Have Not
14. Night of the Hunter
13. This is Spinal Tap
12. Kind Hearts and Coronets
11. Brief Encounter
10. Chinatown
9. The Conformist
8. Vertigo
7. Great Expectations
6. The Battle of Algiers
5. The Lady Eve
4. The Wild Bunch
3. Singin’ in the Rain
2. Double Indemnity
1. All About Eve