And of course, I had to include some of the songs that were part of the little counting skits -- I still think of the old-timey, banjo-heavy "Ladybugs' Picnic" and The Pointer Sisters' jazzy, funky pinball jam when I hear the number 12 mentioned. Rounding things out, the ear-wormiest of the Sesame Street and Muppet Show songs -- "Mah Na Mah Na," written by Italian film score composer Piero Umiliani (for a soft core porn film, no less!) -- which was recently used in a Dr. Pepper commercial, of all things.
Johnny Cash and Oscar the Grouch -- Nasty Dan
Madeline Kahn and Grover -- Sing After Me
Bert -- Doin' the Pigeon
The Pointer Sisters -- Pinball Number Count
The Ladybugs' Picnic
Mah Na Mah Na (follow this link to a clip of the Muppet Show version.)
(Heck, if you've got lots of time to waste, here's a link to all the YouTube clips of Sesame Street moments.)