Well, to be honest, I liked them. Yeah, I said it. I liked them. But I liked them in that, "My son has failed me by choosing to be a drug addict but I still have to love and support him" kind of way.
For me, I really enjoyed the STORY of the prequels. By that, I mean I appreciate and respect the growth and death and essential rebirth of Anakin Skywalker. When you put all six together, it becomes Anakin's story more than it does Luke's, and I can dig that. It's a really compelling story that I think anyone can enjoy. Also, when you look at Luke's and Anakin's characters and compare, the paths are very similar, but they make different decisions.
Where the prequel trilogy goes wrong is the execution of telling that story. The issue here is that, and I think he knows it, is that George Lucas is NOT a director. Matter of fact, he hates working with actors, more than likely why there was a ton of blue screen work. Also, he isn't the best dialogue writer. But, I will say that he is an incredible storyteller.
But then, you might ask, why are the prequels regarded as crap when the originals are held in the highest regard? Would George Lucas not have the same tools as he did before and make another set of excellent movies? Well, you would think that, but...ok, let me explain. The first film (Episode IV) Was written and directed by George. And it was great! The 2nd (Episode V) was co-written by Lawrence Kasdan and Directed by Irvin Kirshner. The third (Episode VI) was again co-written by Kasdan but directed by Richard...ah fuck, I can't remember his name. My point is, ask any Star Wars fan worth his mettle and they can tell you they enjoyed Empire or Return of the Jedi more than they did the original because Lucas had help both in the script and on set. With the prequel trilogy, he probably thought that he could handle all that stuff on his own since he's got all the time and money in the world to make these movies. Not to mention that putting someone else behind the camera and having someone else look at his script was probably not his favorite idea, but he had to do it for the first three films, otherwise he would have gone insane, or had a stroke or something.
In the end, I appreciated the Star Wars prequel films because they expanded the universe and showed us the origin of Darth Vader, although I think I preferred not knowing. The thing about mysteries is that once you know what they are, they lose their power. Which is sad. I look at the prequel films and I smile, but there is immense sadness inside me that I don't want to show, because they could have been something so much greater.