I really don't see the point of this, it is pretty hard to mark a movie liberal or conservative. It also depends on the aspect of the film you look at. I fail to see anything that warrants the use of a superlative regarding the liberalness of the majority of those films.

To Kill A Mockingbird
Schindler's List
Soylent Green
Planet of the Apes

To Kill A Mockingbird is pretty chock full of "conservative" themes (how I hate these silly increasingly inaccurate descriptors more and more everyday).
Planet of the Apes has some pretty conservative themes in it as well, but I suppose you are focusing on the evolution aspect of the film. It is ashame a film with so many great themes to it get
chocked off as "evolutionary propaganda" by "liberals". Kind takes a great work of sci-fi and makes it a pile of crap. Notice the word "sci-fi", this indicates the science described in the movie should not be used to prove anything regarding science in the real world, because it is a work of fantasy. More about social ills than about atheism. Evolution is merely a plot point. And let's not forget Caesar's speech about if it is God's will that apes should rule man, then it will be done with kindness and compassion.
Soylent Green ^ Charlton Heston, same actor who plays in Planet of the Apes is an extreme "conservative". Not that that makes such a difference about the films contents, but I still don't see much "liberalism" about it.
Schindler's List? This is the film about the Jews right? Is it liberal because it contains Nazis?

Do you know why "liberal" and "conservative" are such retarded concepts? Because in the manner we use them today they are pretty non descriptive, very slippery terms. If I claim to be a conservative then who is liberal? Well, anybody who is not as conservative as me. If I claim to be a liberal, who is conservative? Anybody who isn't quite as liberal as myself. One man's conservative is another man's liberal. In a classical sense of the word I am a flaming liberal, just like every other American alive today (including G.W. Bush).

With that said, I will give you Roger and Me and The US vs. John Lennon, for one I have not seen them and another I know anything by Michael Moore is going to be swollen with his backwards intellect like a wound with puss. If I am going to be labeled a conservative, at least Michael Moore is one person I do not have to feel ashamed to share the same affiliation with. If I were a liberal I would be terribly embarrassed to have him on my side.