Invasion of the Body Snatchers Movies: Original Timeline
While the 1978 film is generally marketed as a remake, careful viewers have noted details that suggest it could be a stealth sequel to the original 1956 invasion. The key evidence is a memorable cameo by Kevin McCarthy, the star of the first film, who appears running through San Francisco's streets warning about the pod people - reprising his character's desperate flight from the original's ending.
This watch order treats the films as potentially connected, with the alien invasion spreading from the small town of Santa Mira to the major urban center of San Francisco. The connection isn't explicitly stated, making it subtle enough that the 1978 film works perfectly as either a remake or a continuation of the story.
There is 1 other watch order available – see the link up above.

Invasion of the Body Snatchers
A small-town doctor discovers that the residents of his community are being systematically replaced by emotionless alien duplicates in this classic science fiction thriller.

Invasion of the Body Snatchers
Two health department workers in San Francisco discover that the city's residents are being replaced by emotionless duplicates in this chilling sci-fi horror remake.
Other Film Series
Alien
Humanity's terrifying encounters with a perfect killing organism across centuries of space exploration.
Friday the 13th
The murderous legacy of Crystal Lake and its iconic killer Jason Voorhees in this enduring slasher series.
Halloween
The iconic slasher franchise following masked killer Michael Myers across multiple timelines and reboots spanning over four decades.
REC
Spanish found footage horror franchise following a demonic infection outbreak, featuring intense apartment building quarantine scenarios and their devastating consequences.
The Purge
A dystopian horror franchise set in an America where all crime is legal for 12 hours once a year during an annual event called The Purge.
V/H/S
A found footage horror anthology franchise where each film presents multiple terrifying short stories discovered on mysterious VHS tapes.