Amen Break
The Amen Break is apparently the most sampled 6-second drum loop, like, ever. It actually dates back to the 60's and has been hugely influential in Techno, Hip-Hop, Jungle Beat, Movies, Commercials and Radio.
It's quite interesting, only make sure you clear some time for it - it's 18 minutes long.
I'm somewhat confused about the video though....
[Link]