The Flaming Lips featuring Cat Power - “War Pigs” (Black Sabbath cover, live on Austin City Limits)
Let’s break this down: Wayne Coyne doused in fake blood while wearing an American flag as a cape, a bunch of people in animal suits on-stage, and Cat Power singing Black Sabbath (and doing pretty well, if you ask me, despite YouTube comments complaining that she butchered it).
This was my first taste of the Flaming Lips, channel-surfing past midnight back in 2003. It was a great introduction.