20's - "Phantom of the Opera"

30's - "Gone With the Wind"

40's - "Casablanca"

50's - "On the Waterfront"

60's - "West Side Story"

70's - "The Godfather"

80's - "Raging Bull"

90's - "Schindler's List"

The best decade for films was the 30's (followed closely by the 70's).