Darek Mihocka, proprietor of emulators.com, and whom I linked to a few years ago, released the source code to Atari ST emulator Gemulator 9.0, and in celebration, he also posted his 1992 promotional video to YouTube: Part 1, Part 2, Part 3.
Warning: It's a really bad video. The music, the hair, the cheesy video effects, the bad acting...