One scene that I remember fairly well was when Ramon was lying in his bed alone. It was a medium shot of the side of his bed, and I think it was raining outside. I don't remember when in the movie this took place. This creates a miserable scene, which is supposed to show how miserable Ramon was in his current confinement to the room, which he has been in for a very, very long time.
Another scene I remember is when Ramon is talking to Julia. The shots were almost all close-ups of their faces. This was done to show that the two were growing close, which is very apparent later in the film. It also gives you a personal, uncomfortable feeling, like your spying on them while they're getting ready to kiss.
The third scene I remember was at the end. Ramon is in bed, getting ready to drink the water. The scene is almost entirely one shot, and it makes you feel like Ramon is talking to you, giving you his last words before committing suicide. You are also seeing what others saw when the original video was found. This scene raps the movie up well, because the original video was not intended for people who had just watched a full movie about him, so he tells some things that we already know.