The In-Joke: Mel Gibson is caught in the crossfire during a bank robbery, performing a double-take when he realises one of the robbers is his Lethal Weapon co-star Danny Glover.
Why It’s Great: The in-joke even extends to the music, which manages to work the Riggs theme into the score. And then Glover puts the cherry on the icing on the cake, by quipping, “I’m too old for this shit!”
If It Was Reversed: Riggs proves himself surprisingly handy with a lasso, much to his partner’s bewilderment.
Shaun Of The Dead #1 (2004)
The In-Joke: “We’re coming to get you Barbara,” shouts Ed down the phone to Shaun’s mum. It’s an echo of the first line of Night Of The Living Dead , where a brother scares his sister with the words, “they’re coming to get you Barbara.”
Why It’s Great: Shaun Of The Dead is so jam-packed with zombie in-jokes, it’s hard to single any out for special praise, but this one sticks in the memory for some reason. Top class geekery from Edgar Wright.
If It Was Reversed: It actually has been; Simon Pegg and Edgar Wright had blink-and-you-miss-them zombie cameos in Romero's Land Of The Dead, released a year after Shaun. We deeply wish the line 'you've got red on you.' had made an appearance though.
Shaun Of The Dead #2 (2004)
The In-Joke: Simon Pegg’s merry little band run into a similar posse of British TV stars, headed up by his Spaced co-star Jessica Stevenson.
Why It’s Great: It’s a great visual gag, as Martin Freeman, Reece Shearsmith and Matt Lucas all crop up as Sean and co.’s respective counterparts.
If It Was Reversed: We’d happily watch the same film told from the second group’s perspective. Sequel?
Charlie's Angels (2000)
The In-Joke: Drew Barrymore’s character crashes into a living room that looks more than a little like the one found in E.T.
Why It’s Great: It’s a neat throwback to Drew’s roots, although the E.T. poster hanging above the TV spells it out a little too broadly.
If It Was Reversed: We’d see a leather catsuit hanging in young Gertie’s wardrobe. Might be a bit weird, on second thoughts…
The Lost World (1997)
The In-Joke: As the T-Rex rampages through San Diego, a movie poster is spotted promoting Arnold Schwarzenegger in King Lear .
Why It’s Great: Arnie as King Lear is something we’d genuinely like to see… for about five minutes or so.
If It Was Reversed: Let’s face it, an Arnie-starring King Lear would probably have dinosaurs in it anyway.
Last Action Hero (1993)
The In-Joke: A poster can be spotted for The Terminator , starring none other than… Sly Stallone!
Why It’s Great: Last Action Hero is full of knowing references like this one. A top bit of inter-action hero banter.
If It Was Reversed: Arnie as Rocky? Hey, Hollywood has had worse ideas…
Back To The Future pt 2 (1989)
The In-Joke: Robert Zemeckis pokes gentle fun at his executive producer, by predicting Jaws 19 will have hit cinemas by 2015.
Why It’s Great: The additional detail is excellent, with the holographic movie credited to one Max Spielberg, real-life son of Steven.
If It Was Reversed: One of Jaws ’ panicked sunbathers makes a hasty getaway from the beach via what looks like a floating skateboard.
Home Alone 2 (1993)
The In-Joke: Young Kevin McCallister enters the Plaza Hotel and asks a familiar looking figure where the lobby is.
Why It’s Great: It’s only Donald Trump, isn’t it, then owner of the Plaza. Ridiculous hair, as ever.
If It Was Reversed: Macauley Culkin would crop up as a helpful janitor during The Apprentice . What do you mean he’s not playing a part?
Die Hard With A Vengeance (1995)
The In-Joke: When asked how he’s been spending his retirement, Bruce Willis replies, “I was just getting used to my day job, smoking cigarettes and watching Captain Kangaroo.”
Why It’s Great: Willis sings the same Statler Brothers lyric just before he runs over Marsellus Wallace in Pulp Fiction .
If It Was Reversed: Butch would yell “Yippie-kay-ay” as he ploughs into Marsellus.
Spider-Man 2 (2004)
The In-Joke: Amid the mayhem of the hospital scene, one stricken nurse spies a nearby chainsaw in a callback to director Sam Raimi’s Evil Dead 2 .
Why It’s Great: The whole scene takes its visual cues from the Evil Dead series, and this shot is the icing on the cake. Groovy.
If It Was Reversed: Perhaps a mutated spider might have a part to play in the upcoming Evil Dead remake.