My personal favourite is "The Math Song" by The Darkest of the Hillside Thicketshttp://www.last.fm/music/The+Darkest+of+the+Hillside+Thickets/Spaceship+Zero/The+Math+Song Abusive comment hidden. (Show it anyway.)
http://www.last.fm/music/The+Darkest+of+the+Hillside+Thickets/Spaceship+Zero/The+Math+Song