The X-Files Movies: Release Order
The X-Files became a cultural phenomenon during its original nine-season run from 1993 to 2002, following FBI agents Fox Mulder and Dana Scully as they investigate unexplained cases involving paranormal activity, alien conspiracies, and government cover-ups. The franchise expanded into two feature films that form essential chapters within the larger mythology.
The first film, The X-Files: Fight the Future, was released during the show's peak in 1998 and takes place between the fifth and sixth seasons and delves deep into the series' alien colonization mythology. A decade later, The X-Files: I Want to Believe arrived as a standalone thriller after the original series concluded, notably eschewing the alien mythology in favor of a self-contained monster of the week style story.
While both films feature the iconic partnership of Mulder and Scully, they represent very different approaches to the franchise's storytelling - one expanding the overarching conspiracy, the other providing a more intimate character study in a tense thriller setting. The first film only works if you're familiar with the TV show, while the second feels standalone enough to be enjoyable even if you've never seen the show.

The X-Files
FBI agents Mulder and Scully uncover a government conspiracy that may involve alien colonization of Earth. Removed from the X-Files, they must work outside official channels to expose the truth and fight shadowy forces within their own government.

The X Files: I Want to Believe
FBI agents Mulder and Scully return to investigate a case involving a former priest who claims to have psychic visions about a missing agent.
Other Film Series
Benson-Moorhead Universe
An interconnected indie sci-fi/horror universe from filmmaking duo Justin Benson and Aaron Moorhead.
Cube
A psychological horror series about groups of strangers trapped in deadly maze-like structures, fighting to survive elaborate deathtraps while searching for escape.
Dr. Mabuse
A decades-spanning German crime thriller series following the criminal mastermind Dr. Mabuse through various incarnations, from Fritz Lang's original trilogy to 1960s sequels and later spiritual successors.
H.P. Lovecraft
Feature film adaptations directly based on the works of horror author H.P. Lovecraft.
Invasion of the Body Snatchers
Four films exploring alien pod people replacing humans, each updating the concept for different eras and anxieties.
REC
Spanish found footage horror franchise following a demonic infection outbreak, featuring intense apartment building quarantine scenarios and their devastating consequences.