If you could pick one Nintendo game to become a full length feature film........

[Raven]

Metroid & Star Fox could do well as films I think. Metroid being a more gritty suspense/sci-fi like Alien and Star Fox being a more family-friendly adventure sci-fi movie. Like people mentioned earlier, the two games actually have dialogue so the characters actually have a decent amount of personality to build upon and work with in a film.