Star Wars Episode II on set behind the scenes,
We Didn't Go To The Desert To Get A Suntan
2001-ish. Had the internet before, but can't remember any other videos. I remember listening to Lucas saying, "What you do is you go where the story takes you *mumbles* sometimes you just have to be on location because it demands it" FOREVER on loop as I played back the little that had been downloaded so far.
Edit: not really a classic, lol. As for Youtube videos one of the first I saw was called 'Zorg' or something. It was a thumb with a human mouth on it, amongst various other 240p treats.