3. Seinfeld, "The Strike"
The episode that gave us Festivus for the rest of us! My friends and I actually observe this fake holiday, and "the airing of grievances" has become one of our favorites.
2. Twilight Zone, "Night of the Meek"
The best and wierdest Santa Claus story ever. If you haven't seen it, you really REALLY need to.
1. M*A*S*H, "Death Takes a Holiday"
This is probably the best episode of the whole series. The crew of the 4077th entertain a bunch of local orphans, which adds some much-needed levity to the main plot: BJ, Hoolahan, and Hawkeye work to save the life of a soldier so that his family won't think of Christmas as the day their father died.