Grindhouse Movies: Machete Films
The Machete series represents the only true sequel relationship within the Grindhouse universe. Beginning with Danny Trejo's fake trailer character, these films expanded into their own satirical action franchise.
Both films follow the same over-the-top universe and characters, with Machete Kills serving as a direct sequel that ends on a cliffhanger for the never-produced Machete Kills Again. These films embrace increasingly absurd sci-fi elements while maintaining their exploitation roots.
There are 2 other watch orders available - see the links up above.

Machete
An ex-Federale seeks brutal revenge after being betrayed by the man who hired him to assassinate a Texas Senator.

Machete Kills
Ex-Federale agent Machete is recruited by the President for an impossible mission to stop a revolutionary madman and an eccentric billionaire arms dealer from spreading global chaos.
Other Film Series
Crocodiles
Films featuring crocodiles and alligators as the primary threat, from serious survival horror to campy creature features.
Darkman
Sam Raimi's cult superhero-horror trilogy following a disfigured scientist who becomes a vigilante.
Phantasm
A surreal horror franchise following young Mike Pearson and ice cream vendor Reggie in their ongoing battle against the interdimensional Tall Man and his deadly silver spheres.
Renny Harlin
Finnish director known for high-octane action blockbusters and horror films spanning from the late 1980s to today.
The Crow
Gothic supernatural revenge saga based on James O'Barr's graphic novel, following different protagonists resurrected by mystical forces to avenge their murders.
The Prophecy
A supernatural horror series exploring angelic warfare and humanity's role in the celestial conflict between good and evil.