Atari Tempest and it's Quadrascan Vector CRT Monitor filmed at 50,000 FPS. If you've never seen how the electron gun in a vector monitor works, this explains it. This is so, so extremely my kind of thing.
The thing to know - and this is partly why I love Tempest - is that a vector monitor paints in random / arbitrary lines and directions. This, as opposed to a more common raster CRT that builds up a pixelated frame line by line marching down the tube.