The "Highlander" franchise has six movies, three TV shows, a web series, nine tie-in novels, two comic book titles, a card game, and a video game for the Atari Jaguar.
If one is already familiar with "Highlander" and all its weird interlocking stories, then here is the way to watch the films — more or less chronologically.
The first three are "Highlander" (1986), "Highlander: The Final Dimension" a.k.a. "Highlander III: The Sorcerer" (1994), and "Highlander: The Series" (1992-1998).
Next to watch are "The Methos Chronicles" (2001) "Highlander: Endgame" (2000), "Highlander: The Source" (2007), and "Highlander II: The Quickening" (1991).