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. Here Eddy Fry offers a staggering 538 trillion iterations, but to be honest I'm not all that impressed with the hardness of his zoom:
Here's a "lucky zoom" with 7.777*10^777 | 777,777 iterations:
It is amazing what folks find hidden in the set. The "Pinwheel of Infinity" is a striking example of the uncannyiness of fractals:
….and, from Fractal Universe, the "hardest Mandelbrot Zoom Ever":
You can make your own with Mandelbrot Explorer.