List updated with some notes:
Lucio Fulci’s The Beyond (1981) is the middle entry in the late Italian director’s “Gates of Hell” trilogy which also includes City of the Living Dead (1980) and The House by the Cemetery (1981). The Wrath of Khan (1982) is the first entry in the Star Trek Motion Picture trilogy, followed by The Search for Spock (1984) and The Voyage Home (1986). Both of these trilogies are unofficial but make plenty of sense.
Finally, in regards to Terminator, Indiana Jones and Romero’s Dead films, I have chosen to exclude the subsequent parts in those series due to the fact that they arrived MANY years later and also because those later films don’t really hold a candle to the first 3 anyway (I’m pretty sure that I am not alone in that assessment).
This is all in my own humble opinion, of course. Thanks for reading!Read less