"Well, they certainly seem to be having a good time out there, Sprocket. Yep, I like it when they have a good time."
Almost counts as a bit of a tearjerker, since this was one of the last things Jim ever did with these characters. It's almost like a dad looking in on his kids one last time.
Gonzo trying to convince the Turkey and leave the farm before he becomes Christmas dinner
Emily Bear's conclusion that the Muppet Show gang may be "weirdos, but they're nice weirdos."
The Swedish Chef being comforted by Big Bird's innocent offer of friendship and deciding that Christmas dinner will be "shredded wheat and cranberry sauce."
Robin the Frog and the Fraggles.
And the pebble.
While the Christmas carol singing sequence is heartwarming in itself, hearing Statler and Waldorf (of all people!) singing one of the carols is just adorable. (This is sadly lessened since this portion is cut out of some editions of the special.)
Doc offering to look for Miss Piggy when she's lost in the snowstorm, and explaining why;
Kermit: But you've never even met Miss Piggy!
Doc: Well, we've never met any of you until a little while ago, and now we're friends. See, Sprocky and I were gonna spend Christmas alone, but this is better!