The Thin Red Line. 3 hours to go up a mountain with the most tedious monologues ever. Kept on thinking it was done and it just went on and on.
I thought the same about the book, which I read as a teenager, decades ago. The monologues seemed to go on for about 30 pages at a time, and as they seemed to be about the meaning of war/life, from a Christian perspective, they didn't do much for atheist me.
I actually thought the film was really, really good, in that the monologues were distilled to almost nothing in comparison, but the film still had philosophical and emotional content that makes it really, really different. If you were filtering that out while impatiently waiting for the next plot development, I can see why it would do nothing for you. (I have sometimes read books in that way, I could only appreciate "Heart of Darkness" the fourth time I read it, when I explicitly tried to follow advice to slow down and read it like poetry.)
It's a full-on gory war film that's also an art film. I will bore anyone who will listen about the contrast between the opening and closing scenes, with the aboriginal people, on/near the beach.