I want to throw an idea out there that I don't know if has been suggested before even though i'ts not very "Star Warsy", it could be cool.

So what I was thinking was to have in ROTS Palpatine coming to Mustafar to find Anakin burned but not saying, "And he is still alive". Just have him kneel right next to his supposed corpse, and that is the last we see of him. Then we show Padme's dying speech to Obi wan and we hear crying baby on the background but not see them. Then we see Padme's funeral, later Yoda speaking to Obi Wan about Qui Gon, and then Yoda going to Dagobah (up to the editor). Then the film closes the same it does originally with Obi Wan leaving Luke with uncle Owen and aunt Beru and that leaves intrigue to the audience that Padme delivered the baby and that that's Anakin's son, but most importantly they think that there was only one baby the whole time.

Now this is where it gets "unstar warsy". After the reveal of Darth Vader on Empire Strikes back audience gets surprised and wonder how did Anakin survived and became Darth Vader. So what I had in mind is to start ROTJ even before the crawl, to have sort of a Prologue/Flashback in the style of Lord of the Rings where in the third movie the prologue is gollum's transformation. This Prologue would be sort of a montage of all the things that where kept from us in ROTS. We show Anakin getting in costume and Padme giving birth to twins but still not naming them because Leia has not yet been reveal as Luke's sister by that time. And end the montage with Vader's "Yes master" and fade to black or show Vader and the Emperor on the star destroyer and have them both look at the early Death Star. When the montage ends we see A long time ago, in a galaxy far far away and Rotj starts.