I've looked at a lot of the Twain movies. The two I absolutely cannot use
the musical from Elmira and the mid-30's "Life of Mark Twain".
The Ken Howard "Puddin'head Wilson" (@1985) has been successful for me.
I generally use it prior to reading "Adventures of Huckleberry Finn" and
instead of any movie of "Huckleberry Finn". It helps kids visualize the
setting and get a grasp of some of the issues.