LOTR is a great movie to introduce Christian themes, and I have been working on taking out takes of scenes from the movies to discuss with my older teen youth group, such as:
-The nature and effects of power on people
-The parallels between Smeagol/Deagol and Cain/Abel in the movie.
-Boromir's wrestling with himself, and only understanding the nature of life until he repented (he literally fell flat, and then was brought to his senses). From then he understood it was better for him to give of himself, than to take from others.
It's been interesting enough that I have a group of adults who want to watch the movies and have discussions afterwards. We'll see where that goes, though...sometimes we have troubles actually doing what we want to do.
I really like Ostrog, but maybe that's just me.
But, y'know, you can discuss spiritual themes with Spongebob Squarepants episodes, when you really get down to it! Movies need to have some sort of tension in them, and then you can discuss the spiritual impact of the decisions made by the characters.