Supernatural Season 5 Episode 19

Dean: And you keep an eye on Norman Bates here.
Referencing Norman Bates, the killer played by Anthony Perkins in the 1960 movie Psycho, and its sequels, based on the novel by Robert Bloch.

Dean: Like full-on Babar.
Referencing the title character of a series of children's books written by Jean de Brunhoff. Babar travels out into the world, becomes educated, and returns to create a kingdom of civilized elephants.

Dean: Motel Hell.
Referencing the 1980 movie starring Rory Calhoun as Farmer Vincent, who together with his young sister Ida runs the Motel Hello. That's just a cover for their real business, which is abducting unsuspecting passerbys, planting them in the ground, severing their vocal chords, and eventually slaughtering them as ingredients for their famous smoked meats.

Gabriel: I'm the Costner to your Houston.
Referencing the 1992 thriller The Bodyguard starring the aforementioned actor & actress. Frank Farmer is hired to protect a music superstar, Rachel Marron, who is a stalker's target. During the course of the movie, the two fall in love.

Dean: Or, uh, we tell the Legion of Doom about your secret identity.
Referencing the Legion of Doom, the supervillain organization that first appeared in Challenge of the SuperFriends. The SuperFriends' first actual super-powered opponents, the Legion featured thirteen members: Lex Luthor, Brainiac, Solomon Grundy, the Riddler, the Scarecrow, Bizarro, Cheetah, Black Manta, Giganta, Gorilla Grodd, Sinestro, Captain Cold, and the Toyman. Nine of those villains appear in the JLU version seen here. Each week the Legion would come up with some ludicrously overly complicated scheme to take over and/or rob the world, be defeated by the SuperFriends, but escape at the last minute.

Gabriel: I mean, screw this marble. Let's go check out Pandora.
Referencing the native planet seen in the 2009 science fiction film Avatar. In it, humans attempt to harvest unobtanium and create genetic hybrids to infiltrate the local sapient humanoids, the Na'vi. Released in both 2-d and 3-d, the film received a universally positive reception and became the first film to gross more than $2 billion in worldwide showings. It was nominated for nine Oscars and received three.

Dean: All right, you primitive screwheads, listen up.
Referencing the 1993 movie Army of Darkness, where the hero, Ash, is transported through time and addresses a group of Medieval English villagers using the same dialogue while explaining about his "boomstick."

Gabriel: Lucy, I'm home.
Referencing the classic TV show I Love Lucy, where Ricky Ricardo (Desi Arnaz) always announced his arrival at home in the same way.