Jackson butchered most of the male characters; Frodo was more assertive and had more leadership qualities, and he certainly never told Sam to take a hike. Theoden and Denethor were weakened, and their characters became (in the eyes of my friends who had not read the book prior to seeing the movies) basically identical.
I still think that someone should make LOTR into a television series. That’s the only way to have enough time to do it justice.
All good points. The portrayal of Aragorn irritated me the most, but what you say about the other male characters is exactly right.