Then you should check out Plus! Dancer from Plus! Digital Media Edition. You can see a demo of the dancers here, they dance on your screen to any sound that's currently being played, and you can download additional dancers, from Arkantos from AOM to some swing dancers to a 60s retro dancer.
They're all fun to watch for at least a few minutes, as these folks really are great dancers, and some are just plain hilarious. My favorite is Ben, who does all the dorky dances I remember from school - from “the robot“ to “raising the roof“ to the pee-wee herman dance to what can only be explained as “shimmy shimmy coconuts“. Here's a sample of some of his slick moves:
P.S. “Boo Who” is actually clippy in a ghost costume. I love seeing Microsoft poking fun at itself.