A highlight of Lee J. Cobb's exquisite performance in 12 Angry Men (directed by Sidney Lumet), one of the greatest ever. Warning: spoiler (if there is anyone who hasn't seen it!): link.
One of the many funny bits of "Withnail and I" a British cult classic, and the scene most quoted, I think. "We want the finest wines available to humanity, we want them here, and we want them now!": link.
Here's a strange, surreal thing. "Frontier Psychiatrist" by The Avalanches, which the person posting cites with some possible justification as "the best music video ever". I wouldn't go that far, but it's amusing: link.
MySpace is pretty good for pirate video links as well (though in theory it's all a disgrace and blah blah, sort of like the drugs trade really). There are some good music video links in the scrolling video links section here.