RotS, which I didn't like as many of the other EpI-II haters did, helped me come to one realization:
Return of the Jedi is really cool! Lukes's (albeit breif) turn to the Dark Side at the end is SO much more convincing than anything in the PT. Luke's character arc was character driven. He became what his character had to become (which is really true of all the OT characters, like it or not, I think). Anakin is plot driven. He must turn to the Dark Side to become Vader so he does. Anyways, it's short, but I came away from RotS with a new appreciation for RotJ.
Xhonzi