Lost (TV), episode Not in Portland: “Room 23 is the room in the Hydra station, in which Karl was kept in… In the room, Karl was forced to watch a video while strapped to a chair with an IV in his arm, wearing LED goggles, and being subjected to extremely loud drum-and-bass music.”
This is a reference to A Clockwork Orange (film): “The video from Room 23 is a reference to the Ludovico technique, a fictitious type of aversion conditioning used in A Clockwork Orange. With this technique, the subject is medicated with a pro-nauseate drug and forced to watch a movie with disturbing images and loud music, thereby associating the sensation of being ill with violent ideas. Additionally, Alex’s room number in the prison where he is held before being removed for the Ludovico Technique is 23.”
Star Wars (film): “…Cell Block AA23, where Princess Leia was held in Star Wars IV: A New Hope. This reference furthers the analogy of Sawyer’s explicit reference in the opening of the Room 23 sequence in Lost to “the ol’ Wookiee prisoner trick”, which is used in Star Wars to rescue Leia from Cell Block AA23.”
The Blood of a Poet (film): “In this surrealist film directed by Jean Cocteau, the main character is walking through a hallway of hotel rooms and peeks through the keyhole into the rooms. In room 23, he sees a statue slowly come to life and a hypnotic spiral.”
While we’re at it, we shouldn’t forget the similarity between the episode of Lost and:
The Prisoner (TV), episode A Change of Mind: “…featured the ‘aversion room’, with similar brain washing room features.The film in room 23 even seems to use the typeface “Albertus”, which is similar to the iconic font used on The Prisoner.The text “We are the causes of our own suffering” is also reminiscent of the brainwashing statement in The Prisoner, “questions are a burden to others, answers a prison for oneself”.”
All quotes from Lostpedia.
See also Blather‘s article on the number 23.