Right on, Phantom-like, about the Silmarillion!
The Silmarillion & Unfinished Tales have some of Tolkien's most amazing works. I believe you forgot to mention the Narn I Hin Hurin (tale of the children of hurin) which is complemented by The Tale of Turambar in Unfinished Tales. What a tragic tale that was! Years ago, I always thought that story would be perfect to make into a great movie.
But yeah, it would be impossible to do a movie of the entire book.