Back in the days before Elmo, Sesame Street put out this Christmas special, which teaches kids The Meaning Of Christmas. There is plenty of adult-oriented humor in this to keep parents interested (such as when Big Bird, trying to figure out why Santa hasn't arrived at Sesame Street, theorizes that Santa might be "stacked over Kennedy").
Plot: Big Bird is very excited about Santa Claus's visit... right up until he talks to Oscar. In typical Grouch fashion, Oscar tells Big Bird that Santa, who is "built like a dump truck," can't fit in a chimney - if Santa can't get into people's houses, "there's gonna be a lot of empty stockings around town tomorrow morning." Big Bird is determined to learn how Santa does it, and after trying to figure it out on his own, he heads for the roof so he can watch Santa go down the chimney in person. He falls asleep, but since nobody knows where he is, the rest of the gang spends Christmas Eve searching for him. When he finally gets cold ("I think I froze my giblets.") and comes down to warm up, he's amazed to see that there are presents there, and he learns that it's not important how Santa gets down the chimney - the really important things are friends and family.
Secondary plot: It's Christmas Eve, and Bert and Ernie haven't gotten each other's gifts yet! In a twist on The Gift of The Magi, Bert decides to get Ernie a soap dish to keep Rubber Duckie in, but gives Mr. Hooper his paper clip collection to pay for it; at the same time, Ernie wants to get Bert a cigar box to keep his paper clips in, and pays for it with Rubber Duckie. In the end, Mr. Hooper gives the paper clip collection and Rubber Duckie back to Bert and Ernie as his present to them.
Other plots:
Cookie Monster tries to write a letter to Santa, but keeps eating the writing implement.
Kermit and Grover help Big Bird investigate the Santa/chimney conundrum by interviewing kids.
Songs:
True Blue Miracle - Everyone
Keep Christmas with You All Through the Year - Bob and the kids (with Linda signing)
I Hate Christmas - Oscar
Have Yourself A Merry Little Christmas - Bert and Ernie