Simply the most insane shit fabulously bizarre stuff I've seen online in ages. Educational videos about history, set to pop songs, but that doesn't begin to cover it. The use of songs like "Hollaback Girl" and "Bad Romance" (for the French Revolution) one might expect, but a music video about the Crusades set to "Eyes Without a Face"?
"Black Death" (set to "Hollaback Girl" by Gwen Stefani)