Universal Soldier Movies: Release Order
The Universal Soldier franchise follows reanimated soldiers enhanced into super-warriors, but has undergone multiple reboots and timeline changes throughout its history. The series began with the original Jean-Claude Van Damme and Dolph Lundgren film and has evolved through different continuities and tonal approaches.
This release order includes all feature films in the franchise, though note that two made-for-TV sequels from 1998 exist that aren't listed here. The series is known for its reboots and retcons, so be sure to check out the different timeline orders up top.
There are 2 other watch orders available - see the links up above.

Universal Soldier
A Vietnam War soldier killed in combat is revived 25 years later as part of a military program that creates super-soldiers with android enhancements. When his memory erasure fails, he begins experiencing flashbacks that threaten the entire operation.
Affiliate link - no extra cost

Universal Soldier: The Return
Former Universal Soldier Luc Deveraux must battle SETH, a supercomputer-controlled warrior seeking revenge against its creators. In this man-versus-machine conflict, Luc faces off against a team of deadly perfect soldiers to prevent catastrophic destruction.
Affiliate link - no extra cost

Universal Soldier: Regeneration
When terrorists threaten nuclear catastrophe at Chernobyl, decommissioned Universal Soldier Luc Deveraux is reactivated to stop them. He must face both his original nemesis and a seemingly unstoppable next-generation UniSol in this action-packed sequel.
Affiliate link - no extra cost

Universal Soldier: Day of Reckoning
A widower seeks vengeance after his family is murdered, but finds himself hunted by an army of genetically enhanced Universal Soldiers led by a mysterious commander with his own agenda.
Affiliate link - no extra cost
Other Film Series
Mad Max
A post-apocalyptic action franchise following the lone warrior Max Rockatansky as he navigates a dangerous wasteland filled with marauders and survivors.
Predator
Elite alien hunters stalk Earth throughout history, seeking the most dangerous prey in brutal combat.
RoboCop
A cyberpunk action series about a critically wounded police officer transformed into a cyborg law enforcer in dystopian Detroit.
Ryan Reynolds
Canadian actor known for his quick wit, comedic timing, and action-hero charisma across romantic comedies, superhero films, and dramatic thrillers.
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.
Trancers
A sci-fi action series about Jack Deth, a time-traveling cop from the 23rd century hunting down zombie-like creatures called Trancers.