I'm reposting something I originally posted in this thread:
http://originaltrilogy.com/forum/topic.cfm/Would-it-have-been-possible-to-make-the-PT-in-the-late-90s-early-00s-in-a-way-that-synced-up-with-the-OOT/topic/16670/
Many have said that it would have been impossible to have good prequels without showing the fall of Anakin Skywalker and the rise of Darth Vader, but I disagree. It is true that there would have been less tragedy since we wouldn't know it was Anakin, but here's how I would have liked to see the PT done:
Anakin Skywalker and Obi-Wan Kenobi are friends during the first movie. In it, the Republic falls during the Clone Wars and the Empire is formed. We learn details like the fact that Obi-Wan has had previous apprentices (but they are not named). One of Obi-Wan's former apprentices joins the Empire, so we suspect that he is Darth Vader until Episode V. Anakin marries a woman and she becomes pregnant.
In the second installment, Anakin's darkness is hinted at. About halfway through the movie, we discover that someone named Darth Vader is rising up through the ranks of the Imperial Army (or something of the sort). When we get to see Darth Vader, he is cloaked and hooded with his face hidden, so we don't find out who he really is. Anakin's darkness is hinted at throughout the movie (but is never so obvious that we can readily connect Darth Vader with Anakin). Latish in the movie, we see a hooded figure kneeling before a hologram, but we can't see the face of the person in the hologram (since he is the Emperor, and his reveal would be spoiled if his face was shown). We can't see the face of the hooded figure, and his name is not given, but he is instructed to kill Anakin Skywalker. Then comes the volcano battle. Anakin is defeated and killed (or so we are led to believe) by the hooded figure, who is masked throughout the whole thing. The movie ends.
In the third movie, Darth Vader is still hooded and cloaked the same way as before, but he now has a mask that is reminiscent of the mask we see in the OT. Darth Vader begins hunting down the remnants of the Jedi order. At some point, he duels Obi-Wan. Obi-Wan manages to dismember Darth Vader's right arm and escape. He then visits Anakin's wife on Alderaan, who has given birth since the first movie. She entrusts Obi-Wan with the care of her son (she has had twins and doesn't want to give them both up, but we don't learn this until ROTJ). Obi-Wan is by this point the last of the Jedi besides his former master, whom we next see Obi-Wan speaking to on a swamp planet, though his master is hidden from sight. Obi-Wan tells him that Darth Vader's fighting style is familiar. His old master tells him to hide away on a remote planet until the time is right. We see a spaceship heading towards a desert planet and the movie ends.
It could have been done, it just wasn't....