A trilogy is a pretty abstract notion. You can apply it to almost any three things.
Honestly, I'm not a big movie buff in general. The only movies I own is probably the 'Indiana Jones' trilogy.
One of the traps or the pitfalls of writing a trilogy - or a triptych, or whatever term you want to use - is that the second book can be a long second act to get you from book one to book three, which borrows all of its energy from the first book.
My gut feeling about sequels is that they should be premeditated: You should try to write a trilogy first or at least sketch out a trilogy if you have any faith in your film.
My father loved 'Godard and Truffaut.' He was more artsy. My mom loved the 'Bourne' trilogy; she likes big blockbusters. She loved that I did 'I Am Legend.' My passion for acting came with my passion for movies.
I finished 'The Hunger Games' trilogy, and I love most anything with zombies.
The great thing about a trilogy is that it feels like you've got a beginning, a middle, and an end.
For bedtime reading, I usually curl up with a good monograph on quantum physics or string theory, my specialty. But since I was a child, I have been fascinated by science fiction. My all-time favorite is 'The Foundation Trilogy,' by Isaac Asimov.
I think the danger with using the term 'trilogy' is that it sets up particular expectations in the reader's mind.
Many fantasy novels - 'Lord of the Rings', for instance, or 'Lavondyss' by Robert Holdstock - are beautifully written. Geoff Ryman's 'The Child Garden' is exquisite and utterly beguiling. Mervyn Peake's 'Gormenghast' trilogy is an astonishing piece of multi-faceted storytelling. So quality of writing does not condemn the genre.