THX-1138, abysmal? I beg to differ. Really, I mean, THX doesn't supply popcorn thrills and high speed space chases, but it's a far deeper and more provacative movie than anything Lucas has done sicne, including Star Wars. I would argue that the Star Wars films and THX aren't even in the same playing field when talking about Lucas' movies. The SW films are mythology-rooted epics that are first and foremost meant to entertain, whereas THX-1138 is a stark distopian nightmare of a film that parallel's Plato's analogy of the cave perhaps better even than the Matrix.
I realize that this is a Star Wars site, and as such may focus in on the lowest common denominator of filmed entertainment-thrills and spills and laser blasts and chest-thumping heros and damsels in distress-- but I would urge anyone with an interest in films with a message, or films that challenge you to use parts of your brain not immediately stimulated by AT-AT Walkers to check out THX-1138. It's some of Lucas' best work.