One movie that immediately sprang to my mind when reading the question was *David Lynch*'s 1984 adaptation of [*Dune*](http://www.imdb.com/title/tt0087182/). It employs a very direct and obvious way of sharing a character's momentary thoughts, **just having them spoken in from the off in the respective situations**.

However, I would still regard that as significantly different from the other narrator-based examples you listed, since in this movie there is no narrator otherwise (well ok, apart from the beginning (and end?)) and those thoughts are not merely done for one protagonist but for a multitude of characters. It's maybe similar to a classic monoloque but with the actor **not visually speaking and *not* directing it at the audience**. It feels much more **situational and immersive** than a fourth wall breaking monologue or a narrator (who always gives the impression of the action having already happened), like you're really hearing the actual thoughts *right now* and without the actor's/character's knowledge.

To me this technique was always something pretty unique and extremely effective about this movie. In the scenes where it was used it made a great contribution to overall atmosphere of the movie. This is also why I wouldn't say this was so much of a narrative story-telling device there, but much more of a **stylistic device**, having the audience not just *know* the plot, but even more so *feel* the characters' emotions. I also don't know if those particular thoughts were actually adapted from the source material at all.

But I haven't seen this technique used anywhere else, only (but more rarely) in the 1971 movie [*The Beguiled*](http://www.imdb.com/title/tt0066819/), albeit being quite an obvious way to share a character's thoughts. But maybe it is too obvious and regarded lazy or pretentious, a "cheap trick" in a medium that allows for much more elaborate ways to *show* rather than *tell* the characters' thoughts and emotions. But sometimes the obvious way might just be the most direct and effective, and for me this was the case in this movie, although I agree that this assessment is rather subjective.