Invasion of the Body Snatchers - Watch Order: 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.

Invasion of the Body Snatchers
The residents of San Francisco are becoming drone-like shadows of their former selves, and as the phenomenon spreads, two Department of Health workers uncover the horrifying truth.
Other Film Series
28 Days Later
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A Quiet Place
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Friday the 13th
The murderous legacy of Crystal Lake and its iconic killer Jason Voorhees in this enduring slasher series.
REC
Spanish found footage horror franchise following a demonic infection outbreak, featuring intense apartment building quarantine scenarios and their devastating consequences.
Romero's Living Dead
George A. Romero's groundbreaking zombie saga, featuring classic horror films and several reboots.
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.