1.In Love Actually, Harry calls his wife Karen a saint before she walks away at the Christmas party. He's then approached by Mia (the woman he cheats on Karen with) who is dressed as a devil.
2.In White Christmas, Phil tells Bob at the beginning of the movie, "I want you to get married, and I want you to have nine children." In the final scene, you can see Bob and Betty surrounded by nine children.
3.In Elf, Buddy and Jovie name their daughter Susie after Buddy's biological mother, Susan Wells.
4.In Christmas with the Kranks, Luther and Nora are wearing the same bathing suits as the people in the advertisement that inspired them to go on vacation.
5.In The Santa Clause, you can see an elf sitting behind Charlie during career day.
6.And in The Santa Clause 2, Santa says the same line that Buzz Lightyear says in Toy Story (both roles are played by Tim Allen).
7.In The Polar Express, the Christmas tree stands on the center of the North Pole. You can tell because there is a compass underneath with every direction pointing south.
8.In Home Alone, the music that accompanies Old Man Marley
changes from "Dies Irae" to "Carol of the Bells" when Kevin finally realizes he isn't scary, signifying a change in judgement.
9.Also in Home Alone when Harry is dressed like a cop, you can tell something's a little off with him because he's wearing a gun-shaped tie clip.
10.You can also see the exact moment in Home Alone where Kevin's ticket goes missing.
11.In The Muppet Christmas Carol, Michael Caine's character stands in front of a shop called "Micklewhite's." Maurice Mickelwhite is Caine's real name.
12.In How the Grinch Stole Christmas, Martha May hangs green stockings instead of the standard red ones 😏.
13.Charlie Chaplin makes a cameo in The Year Without a Santa Claus.
14.In National Lampoon's Christmas Vacation, you can tell Eddie is wearing a dickie under his sweater instead of a turtleneck.
15.In A Christmas Carol, Scrooge's grave says he was born on February 7, the same day that Charles Dickens was born.
16.On Jack's blackboard in The Nightmare Before Christmas, you can see he multiplied 12, 25, and 93, which is the date of Christmas the year the movie came out.
17.Finally, in Die Hard, Ellis tells Holly to show John the watch he gave her. John says "I'm sure I'll see it later," foreshadowing the moment he unlatches it from her wrist causing Hans Gruber to fall to his death.