I love mandelbrot youtube, where the most important thing is how many iterations is in your deep, hard zoom. Here's "Mandelbrot zoom to 10E+1116 with deep zoom into minibrot - 75,000,000 iterations": Or how about some "Mandelbrot deep zoom to 10E+2431 at 60 fps - Needle Julia evolution - 30,000,000 iterations." Very satisfying: Granted, that's not quite as many iterations as some.