Colin, yes, John Williams used the theme of the Jedi as a leitmotif throughout all those scores. However I meant that it finds its fullest expression as a real piece of music and a complete little march melody in that "awards ceremony" or whatever at the end of the first movie.
Mancini - of course Paul! Great suggestion.
I notice how often John Barry comes up when melodies are mentioned. Though he can't match John Williams for pure "efficiency" at film scoring (can anyone?) nevertheless I tend to agree with Dave that Williams does not quite match Goldsmith or John Barry in the invention of melodies. Though they are all great composers, of course. It is more that Williams has a focus on overall, "symphonic" scoring, which favors motival construction, whereas Barry uses long, highly developed melodies. Though Goldsmith could do either. Come to think of it, Goldsmith could do anything. He seems limitless as a composer, though he worked strictly in film music.