This is complete goosebump-o-rama to me: LFT explains a classic C64 tunnel demo effect which is ultra-nerdy and super impressive.
It looks great, it's very clever, it uses known tricks in a new, original way, and it's really well explained. Even mediocre coders like me could implement this after he provides the "aha!"-moment.
If you ever owned a Commodore 64 and coded a little on it, you might enjoy this: