I liked the lighting in ESB best because Kirshner knew how to make something look naturally lit. Every single interior shot in ANH (well...cantina aside I guess) is so brightly and perfectly flushed with lights. Even the trash compactor is lit as well as the hallways on the Death Star. I know someone posted a link to an ESB appreciation page that points these things out so well. The most realistically lit and convincing shots in SW are the outdoor ones....because even GL can't control the sun.......yet.