I appreciate what you're saying, fireproof, but let's not forget something, here: George Lucas wrote AND directed STAR WARS '77 where the acting and interactions betwixt the cast was engaging and entertaining. American Graffiti is also well-acted. It's not like George Lucas couldn't direct actors, ever. That's a crock of shite, but I do love how he deflects criticism of the STAR WARS prequels with this excuse of "Oh! What are you complaining about? I NEVER directed actors well ... that's nothing new." He just lost interest in it, or lost his talent in it, or both. But he didn't want to have to come out and admit that, especially when the prequels were still being released -- who would? And with so much of his own money vested into the project, there was no way he was going to let a more capable director take all of the credit for THE RETURN of STAR WARS -- it had to be Lucas' handiwork, unfortunately. The Phantom Menace seems to have gotten the most attention, script-wise, from George and it's incredibly thin and derivative. All of that time he had to work on it and it comes across like something he wrote on the shitter, for the better part of an hour. This shocks the living hell out of me, considering all of the hype it had to receive.
A NEW HOPE is not a deep movie, but it's treated like it's really happening. Its believability is helped out enormously by the fact that so much of it happens on real locations. Tatooine is being represented by a real desert. Uncle Owen's unusual household is a real location, it's not a set. Yavin is a real location. The temple there, if I'm not mistaken, is real. The costumes of Vader, stormtroopers, the robots ... all of it looks futuristic, yet practical. Yes, you can tell that 3PO's a sort of Knight's outfit, but as a robot, the suit's still very believable. The landspeeder really bobs and stuff, when Luke's getting on and off of it and looks right. And when we do go to artificial environments, they are not overdone, they are low-key ... basically, just a lot of big, open areas with a lot of lights and sliding doors. Best of all, most of this could be interacted with in a very convincing way, because it was real. The CGI in the STAR WARS prequels looks quite real, at times -- especially the matte paintings -- but its very nature made it impossible to have convincing interactions with the cast. Physical contact is rarely required in the films. The aliens are goofy-looking and off-putting, for the most part. And where Lucas finds ILM doing something wildly successfully, like showing CGI terrain speeding along like actual terrain, on-camera ... it becomes a movie, within itself, because Lucas wants to show it off. Had he shown this much interest in the characters, as he had to do with A NEW HOPE, the prequels would've been frigging' phenomenal. There still would've been stupid shite in it, like Annie being a little slave boy and obviously computer-generated, retarded-looking aliens, BUT ... it would've been much more fun to watch. Especially with that cast.