In favorite order but Gone With The Wind and Casablanca are both among the greatest over multiple generations.
Gone with the Wind 1939
Casablanca 1942
King Kong 1933
Miracle on 34th Street 1947
Maltese Falcon 1941
The Grapes of Wrath 1940
And anyone interested in classic films can get on my movie only ping list (if you're not interested in news and sports, too, that is) to receive notice when I post movie reviews on the 70th anniversary of their original publication dates. After 'Gone With the Wind' there are some good ones coming up in 1940.