the Twins
The reason for the inconsistancies with the twins (remembering Mother, another Skywalker, etc) is because they were never supposed to be twins in the first place. There's a great interview with Gary Kurtz on Film Threat that clears that up. Here's an excerpt about Jedi:
"...so the story was quite a bit more poignant and the ending was the coronation of Leia as the queen of what was left of her people, to take over the royal symbol. That meant she was then isolated from all of the rest and Luke went off then by himself. It was basically a kind of bittersweet ending. She's not his sister that dropped in to wrap up everything neatly. His sister was someone else way over on the other side of the galaxy and she wasn't going to show up until the next episode..."
Also proof that they had intended to make 7-9, incidentally. Aahhhh, Lucas the historical revisionist strikes again! (Whole article is here:
http://www.filmthreat.com/Interviews.asp?Id=8)
But I don't mean to be negative. I could nit-pick the ways that the 2 trilogies don't match up (and I have) but overall I really enjoy them. There is some terrific stuff in all 3 movies that I've wanted to see since I was a kid, and I just ignore the crap parts (jar-jar, dax, areana battle, droid factory, the fact that Grievious sounds just like Triumph the Insult Comic Dog, etc).
In fact, there was one thing I really liked that I haven't seen anyone else mention. Anakin's decent is largely driven by these visions he has...he embraces the dark side to save his wife from dying in childbirth. But, had he listened to Yoda, he wouldn't have joined the darkside and then Padme would (probably) have been fine (oh, the irony!). Anyway, as a kid I always thought it was cruel of Yoda to tell Luke not to go and save his friends on Bespin...but now it makes more sense. Yoda is thinking, "shit, see what happened when Anakin didn't listen? He created the pain in the vision! Not again!"
Anyway, I have fun with the prequels looking for stuff like that to latch onto...