I wanted to step aside from my usual topics and discuss one that I think is deadly serious: the presence of Han Solo in Return of the Jedi.
If you watch as many Star Wars documentaries and "making of" films as I do, you know that Harrison Ford asked George Lucas to kill off his character in The Empire Strikes Back. He (Ford) felt that Han had already made the switch from self-serving scoundrel to supportive rebel. If you watch the DVD commentary from Lucas on Empire you know that Lando Calrissian is meant to be character-wise who Han was in the first (or fourth) film. He's only looking out for his own interests and hasn't yet made the jump to supportive of the rebel cause.
However, at that point in the series Han has not made the jump either. True he's helping the rebels and staying there, but now it's out of love for Leia and friendship with Luke. He still hasn't committed to sticking around beyond having sympathies with these people and doesn't yet see the cause as his own. Not until the last movie does General Solo actually get ready to lead an expedition to the moon of Endor without even asking or volunteering any of his friends. He's so in support of the cause he initiates it on his own. That's full circle. That's why Han Solo needed to be in Return of the Jedi.