The Star Wars movie soundtracks are all thematically quite similar, so they're pretty much all equally good. If I were to pick just one for a game soundtrack, I guess I'd go with "Empire Strikes Back".
However, I do recommend the soundtrack for the "Clone Wars" film that was released - it's both distinctly Star Wars and distinctly different enough to avoid pulling players out of the game. If you can find it, there was also a "Shadows of the Empire" soundtrack produced to go with the novel of the same name, which is probably worth considering.
I'm not familiar with any of the video games, so can't comment on the soundtracks.
Of course, you might also want to consider some other appropriate soundtracks. "Blade Runner", perhaps, or even something like "Ronin" or "Heat"?
