Last night’s Glee left a little something to be desired in the “Christmas episode” department. It’s not easy to do a great holiday installment, but it is possible: The O.C.’s Chrismukkah episodes are all solid (though the first season’s is best), Fraggle Rock’s “The Bells of Fraggle Rock” makes magical Muppet paganism beautiful, and “Simpsons Roasting on an Open Fire” gave Santa’s Little Helper a permanent place in the Simpsons mythology. Doctor Who has celebrated in a number of ways, and The West Wing used its Christmas episodes as annual Emmy bait. Seinfeld. Futurama. My So-Called Life. Scrubs. South Park: What’s TV’s best holiday episode?