I'd probably have to say "The Bells of Fraggle Rock", just off the top of my head.
It sort of links several 'holiday' points in my life: seeing the show in my teens when it first aired on HBO; discovering it again on VHS when my stepdaughter was still a teen; and watching it on DVD a couple of years ago with my oldest son, who is now eleven.
My oldest son has never indicated any tendencies towards the 'completist collector' gene that my mother, older sister, youngest son, and I all possess... but as soon as he saw a three-episode DVD of Fraggle Rock, he said solemnly, "I want ALL of these." Last Christmas/birthday, he completed his collection with the Final Season boxed set and the Complete Animated show.
The other day, we watched "Muppet Family Christmas" for the first time, and he liked seeing Kermit and Robin encountering the Fraggles.
Anyway, back to "The Bells of Fraggle Rock", that song in the finale always makes me tear up, but in a happy way.
Dearth