Joe Raposo's best known for his work with Sesame Street, having composed "Sing (Sing a Song)" and "Bein' Green." He's done some other pretty great stuff, too (including the Three's Company theme and four songs on Ol' Blue Eyes is Back; the record company talked Sinatra out of recording an entire album of Raposo songs).
But you all know me; I've got to focus on the kiddie stuff.
A couple of big favorites of mine are "Take a Bweaf" and "There's a Bird On Me."
He performed the vocals for more than a few of the Sesame Street songs, in a really nice tenor voice; this is him singing "Trying and Trying Again" and "Somebody Come and Play."
And here's the man himself acting out a battle with the letters "UN." I'd say his gift for physical comedy is on a par with that of his songwriting.