I love the classic movies. As I type this, I'm watching "The Bachelor and the Bobby Soxer" with Cary Grant, Myrna Loy and Shirley Temple. HILARIOUS movie. Here's a scene:
Another of my favorite movies is "My Man Godfrey". My favorite line comes in a scene that is 5:16 into this clip. "The only difference between a derelict and a man is a job."
I also love many of the Frank Capra movies. "Meet John Doe", "Mr. Deeds Goes To Town", "You Can't Take It With You", "Mr. Smith Goes To Washington", "Arsenic And Old Lace" are among my favorites. They not only teach of morals, but also of consequences. Sometimes it resulted in screwball comedy, but many times the best scenes didn't contain comedic value, but rather a serious tone to drive home the central plot of the story.