As a young child, I had most of the songs from Mary Poppins memorized and I took joy from every scene. I still love that film and think that Julie Andrews is a remarkable performer. There is so much to love about that film. Dick Van Dyke is truly funny and three of the songs: "Sister Suffragette", "The Life I Lead", and "Fidelity Fiduciary Bank" are brilliant social satire, poking fun at the thinking in a lighthearted manner, yet still skewering the hypocrisy. And the theme of the film as the maturing of the head of household instead of the children is brilliant. Still one of the best films ever.
As a young teen, my favorite film was the epic The Ten Commandments. While I still can appreciate the work involved, the film and story I appreciate much less.