"The Christmas Party" - The Office
The first (and best) Christmas-themed episode of The Office. Michael forces everyone in the office to partake in a yankee swap after he's unhappy with his secret santa gift. It's also the episode where Jim panics about Pam getting her gift, and takes back his letter before she can read it.
"The Best Christmas Story Never" - American Dad
Coming around the time when the political correctness of holiday season was entering the national debate, this episode starts out as a politicized send-up of "The Christmas Carol" but morphs into a trippy time travel adventure as Stan's ditzy ghost of Christmas past (played by Lisa Kudrow in one of the season's bests roles) accidentally alters the timeline and Stan has to redo the Reagen Assassination to save Christmas in the present. It was not just a hillarious and self-assured episode but was also one of the best early uses of Roger as he was gradually flanderized from a lazy alien who hung around the attic to a master of disguise.
"Roman Holiday" - Gossip Girl
Serena and Dan are newly in love. They obviously have opposite budgets, so they want to get something meaningful. Dan gets her a real Christmas tree and Serena makes him snow....and then they have sex for the first time in the snow room. Ohhh yeahhhhh.
"Abed's Unconrollable Christmas" - Community
This aired back in Community's prime. We've got claymation animation, a musical number, John Oliver, and a Christmas message of friendship that is heartfelt and sweet without being cheesy and syrupy. This episode was a near-perfect half-hour of television.
"The Santa in the Slush" - Bones
This was a great Bones Christmas episode. There was some Brennan family bonding, in jail, Jeffersonian bonding, and, oh yeah, Booth and Brennan had their steamy 1st kiss (on the show) under the mistletoe.
"Simpsons Roasting on an Open Fire" - The Simpsons
This is he iconic series premiere of a show that is still going 26 years later. When the family hits financial troubles and are unable to buy Christmas presents, Homer and Bart go to the race track praying for a miracle. They lose their bet, but gain a new member of the family when they adopt Santa's Little Helper.
"Amends" - Buffy the Vampire Slayer
Angel is haunted by the First Evil, which makes its first appearance in the series. It's heartbreaking to watch Buffy plead with Angel when he is convinced the only way to stop himself from hurting anyone else is to die by the sunrise. Thankfully he is saved by a miracle California snowstorm that serves as a sign that he still has more good left to do.
"The Best Chrismukkah Ever" - The O.C.
All of The OC Chrismukkah episodes were good, but none will compare to the first one, where Ryan (and the rest of the world) was introduced, courtesy of Seth, to the most joyous holiday ever created – Chrismukkah (Christmas and Hannukah). Seth may never have had to choose between the two holidays, but this year, he was forced to choose between a comic book making Anna and a Wonder Woman donning Summer. Tough choice. In the end however, Seth pulled a half-assed “Kelly Taylor” and chose neither of them without really choosing himself either. In true OC fashion, that wasn’t the only drama to go down – Marissa added shoplifter to her growing resume of issues, while Kirsten held evidence against her father that could’ve gotten her fired. If that weren’t enough, this was also the episode where we met future looney tune, Oliver Trask. And yet…in spite of all of this, the magic of Chrismukkah still found its way into Ryan’s heart. He hung his stocking above the fireplace and joined the Cohens in the family Christmas card. Happy Chrismukkah! Now where’s my yamaclaus?
"The Strike" - Seinfeld
A Festivus for the rest of us! Who doesn't know that phrase? Kramer wants to resurrect Festivus, which George's dad says he invented as an alternative to the commercialism of Christmas. When George creates a bogus charity in lieu of office Christmas presents and his boss donates $20,000, he wants to know what's going on. George says he was persecuted for his celebration of Festivus instead of Christmas.
"Mr. Hankey, the Christmas Poo" - South Park
Poor, Jewish Kyle is feeling left out of all the Christmas festivities. He's visited and comforted by Mr. Hankey, the Christmas Poo, who only comes alive when Kyle's around so everyone thinks he's lost it. It was the first musical episode and also the first when Kenny didn't die. It's a miracle!
"O Come All Ye Faithful" - The Vampire Diaries
While not a Christmas episode in the traditional sense, The Vampire Diaries season 4 episode 9 contained one of the most beautifully brutal massacres in the franchise. "O Come All Ye Faithful" will never be quite the same. RIP Carol Lockwood!
"The Bath Item Gift Hypothesis" - The Big Bang Theory
The Bath Item Gift Hypothesis is still one of the funniest Big Bang Theory episodes to date. Sheldon's reaction when Penny gives him the napkin with Leonard Nimoy's signature (and DNA) is priceless. It meant so much to him that all of the gift baskets weren't enough and he gives her a rare hug. As Leonard said, "it's a Saturnalia miracle!"
"Do You See What I See" - Eureka
When the Super Photon Generator, a massive holographic matrix meant as Jack's Christmas gift for the kids goes awry, they residents of Eureka are all turned into some type of character from holiday favorites, including Rass/Bankin claymation, traditional cartoon and even a look similar to The Polar Express. The holiday episodes are standalone so you can watch anytime and enjoy.