Super Mario Bros., the animated one from a few years ago. I can't speak to the more recent Galaxy one as I never played that game, but it was pretty. I enjoyed both, but the first animated one was a good adaptation.

Mortal Kombat from 1995 is considered pretty good. It's a cringe-worthy kung fu movie, but most kung fu movies are cringe-worthy. It is a good adaptation, however; one of the best.

Final Fantasy: The Sprits Within had the advantage of not adapting a game, but being set in a franchise where no two games (at that point) were connected. Final Fantasy VII: Advent Children was a sequel to Final Fantasy VII (7), and was also pretty good.