Here's a Christmas episode so brilliant and influential that it helped popularise its own holiday, Festivus. In the show, it's a holiday devised by George's father as a substitute for the overtly commercial pressures of Christmas, whereby there is an aluminium "Festivus pole", meatloaf dinner, and guests can do things such as air grievances with their family and also try to best them in tests of strength. Best of all? The show's customary banter results in characters declaring regular events to be "Festivus miracles", a hilarious thumb-in-the-nose at the overt preciousness with which people can regard the holiday period. It's an episode so well-regarded that Festivus is actually celebrated by many families the world over, a great way to be cheap (c'mon, it's George!) while also snubbing the stress-inducing importance that some place on the day. On December 23rd, you can kick back, relax, air some grievances and maybe even have a swing on the Festivus pole; get ready.