In particular, a couple of them, while targeting children, are a joy for adults to listen to as well: Philadelphia Chickens and Blue Moo. (No, the latter doesn't have anything in the style of the Marcels.) They feature quite an array of performing talent, and the lyrics and music pay tribute to the styles they adopt rather than parody them.
By far the best is "Mersey Lullaby," performed by Gerry and the Pacemakers. Had this sweet ballad been released in the day of "Ferry Cross the Mersey," I believe it would have been a hit for the group.
Thank you, Ms. Boynton, and thank you, gentlemen. You never lost the magic.