It has been some time since I've seen one, but the most recent one I have seen was Pokemon: Kyurem vs. The Swords of Justice, which was a few years ago. Half the reason I remember the film was that Vic Mignogna was the voice of Keldeo. It was a simple, but a pretty solid movie.
((On another note, I did end up catching the Swords of Justice in Pokemon Black some time after seeing the movie; but unfortunately for me Keldeo was event-exclusive.))