1.) Matrix 1999
Originally the actor that was going to be Neo was Will Smith but he turned down the offer, next was Nicholas Cage but he also turned down the offer. That's when Keanu Reeves got the role.
2.) Indiana Jones and the Raiders of the lost ark 1981
The popular scene where Indiana Jone shoots the menacing swordsman was originally going to be a whole fight scene but since Harrison Ford was not feeling well, they simply turned it into the famous gun vs sword. Many actors were taken into consideration for the role of Indiana Jones, including Sam Neill. Concept art implies that the villain named Toht was originally going to have a Cybernetic left arm but Steven Spielberg thought it was unrealistic. This concept would be used for a Villain in a Indiana Jones novel.
3.) Indiana Jones and the last Crusade 1989
The original story was suppose to take place in a haunted castle but they decided to change the story to make it a father-son story along with the Holy grail being the item of interest.
4.) Goldfinger 1964
Probably one of the most famous James Bond henchmen is "Oddjob" a Korean man who is mute, has almost superhuman strength and durability. The actor who plays as oddjob was a professional wrestler and Olympic weight lifter in real life known as Harold Sakata. Originally a Authentic wrestling match between Harold and another wrestler named Milton Reid was supposed to happen, the winner getting the role of oddjob. The match never took place since Reid already had a role in a previous James Bond film. So Harold was given the role of Oddjob. Also in Oddjob's final scene, Harold actually burnt his right hand during the making of that scene. So the reaction was partly authentic
5.) Patt Roach's multiple roles in Indiana Jones
Indiana Jones fans remember that famous fight scene by between Indiana Jones and the big German mechanic who is played by Pat Roach. Pat roach also played the big guy in the bar gun fight in the Raiders of the lost ark. So basically both of Pat Roach's characters died in one film. He also played the big thug in the temple of doom, sure enough his character also died in that film. He would then play a Gestapo agent in the last crusade. Originally there was a extended scene with the big gestapo agent but it got cut from the film along with some other scenes.
6.) Quarantine 2008
A found footage zombie horror film, basically this is a remake of the Spanish horror film called "REC". The plot is similar, the only difference is that the origin of the zombies is a result of a mad scientist's experiments, while in REC the zombies are of supernatural origin. Both of these movies would get sequels. The sequels are of different plots.
7.) Paranormal activity series has a spinoff
It's called "Paranormal activity Tokyo night" It takes place in Japan, it has some references to the original Paranornal series and it's implied that there is some sort of connection between the spinoff and the original series.
8.) Indiana Jones 4 would have happened in the 1990s
A Indiana Jones film titled "Indiana Jones and the Saucer men from Mars" was in the works in the 1990s but it eventually got cancelled. It's said that parts of the story were used in The Kingdom of the Crystal Skull.
9.) Alien agent 2007
The protagonist on this Sci fi action film is Mark Dacascos who plays a role as a friendly Alien disguised as a Human who needs to save Earth from hostile aliens. Originally Dolph Lundgren was going to get the role before Mark Dacascos was offered the role.
10.) Iron sky series
This comedy film series is actually based on a dream somebody had. It also has references to some conspiracy theories that some people believe about Nazis in Space and in the center of the Earth. The first film involves Nazis invading Earth from their secret moon base and it takes place in 2018 while the second movie which is said to be released this upcoming year, takes place a few years later and features a "lizard race" that lives in the center of the Earth with Hitler being one of them.
11.) Tomorrow, when the war began
A Australian film where Australia is invaded and occupied by a fictional foreign country. This movie is based on a book series(7 books) called "Tommorow" and it was made with the intention of there being sequels. The first movie tells the story of the first book. A second movie was in the works but it was canceled, so basically the movie series was left on a positive cliffhanger. It's possible that this would have been a saga.
12.) Ip man 3
During the making of the popular fight Scene. Donnie Yen accidentally broke one of Mike Tyson's index fingers.
13.) Go for broke 1951
A war movie about the 442nd RCT of the US army during WWII. A lot of the actors were veterans of the 442nd RCT in real life.
14.) Suburban Commando 1991
Famous professional wrestler Mark Calaway(the undertaker) makes a brief appearance in this film. The man on the right in the picture.
15.) Skyfall 2012 and Spectre 2015
Many people assume that All of Daniel Craig's bond films follow the same timeline, Skyfall and Spectre are said to actually follow a different timeline from Casino Royal and Quantum of Solace. Also, although not confirmed; this might explain why James Bond in Skyfall and Spectre seems to be more of a traditional Bond than the "Jason Borne esque" Bond of Casino Royale and Quantum of Solace.