I though Revenge of the Sith was the best but only because of the transformation into Vader, it was the final piece in the jigsaw, although his Noooooooooo at the end was pump. ( new buzzword )
Although Phantom Menace was not as good as I thought, the pod racing was superb and the scene when Darth Maul was waiting in the doorway for Qui-Gon and Obi-Wan, then ignited his double edged saber was even better.