For me, Star Wars is the most cinematic of franchises. Story and style trump realism. It requires a cinematic/narrative-focused game system to properly complement it. Personally, I think FATE is the best fit. Especially when you consider the built-in mechanics to level out characters of differing power levels.
Any system should be relatively streamlined and fast-playing. Star Wars, with its pulp origins, is supposed to dynamic and dramatic. You're off to a cool new location every 15 minutes. Any system that takes an hour to play through a combat is a non-starter for me.