"Sweet Gingerbread Man", by The Mike Curb Congregation. If anyone offers to play you this song, run, screaming, in the other direction, with your hands over your ears. Hear it once and it will insinuate itself into your brain, appearing when you least want it to: when you have been woken up by the 11-year-old in the middle of the night and just want to get back to sleep; spending some quality time with your favourite person; trying to concentrate on umpiring a game of under-10s cricket; having a serious conversation with the Chief Justice of Australia.
Of course, you can always just give in to it. That's what I do. But beware: as the title suggests, this song is so full of sugar that prolonged exposure will cause all your teeth to fall out.