I have shown the '7 minutes of terror' video every time I go in to my kids school for the Hour of Code events.

https://www.jpl.nasa.gov/video/details.php?id=1090

I gives me the chills every time I watch it and is a great starting point to talk about how software / engineering can solve cool problems. I also like that it has both men and women from various ethnic backgrounds.

Another video I've started showing is the Human-Machine brain implant helping this quadriplegic control his arm again: https://www.youtube.com/watch?v=_6oNoLWcDqw

With that all said, I show these specific video as they are enabled with the tooling my company produces and I think that's an important part of the message as it helps connect the dots between the presenter (me) and the uses cases shown.

Good luck!