Nintendo sex education
At first I assumed this video was an elaborate hoax -- just because it's so corny. But if you watch it all the way through, you'll find that Mario and Luigi actually give accurate information about puberty and human reproduction, and some fairly sound advice about unwanted pregnancy and STDs.
While the video is sure to induce giggles amongst even the most mature pre-teens, it's far more engaging, straightforward and fun than the awful sex-ed videos I was shown as a kid. After all, who doesn't love the Mario Brothers?