I suppose I should talk about ROTJ now.
Well, I was born in '89, so I never saw the original originals in theaters. I first saw the trilogy in '93 or '94, and wore out my VHS tapes long before the SE came out in '97.
But I watched ROTJ all the time as a kid. My favorite film was always ESB, but every scene with Luke, Vader, and the Emperor in ROTJ was pure gold to me as a kid. That's what I loved about Jedi.
Even as a 5-year-old, I would fast-forward through Jabba's palace and Endor, with the exceptions of the speeder bike chase and the sail barge fight. The space battle didn't even interest me that much. But the climactic lightsaber duel was my favorite moment of all 3 films.
It took me until a couple of years after the SE came out (possibly after TPM, maybe before) to really realize how inferior ROTJ was to the rest of the trilogy. Another Death Star? How lazy. Vader does basically nothing in the first 3/4 of the movie? Lame. The Ewoks? Don't get me started on the teddy bears that defeat "an entire legion" of the Emperor's "best troops."
And the number one, biggest thing that has always bothered me - from the first time I saw it until today - is the revelation that Leia is Luke's sister. It just smacks of "We have to top 'I am your father' somehow!" It just felt ... wrong. It didn't belong. And it still doesn't.
The other problem I have with it (and this might actually be bigger than the Leia-is-Luke's-sister thing) is that you never feel like the main characters are in any real danger.
You got that in SW, with the Death Star coming so close to destroying the rebel base, and Vader having a clear shot at Luke until Han finally sees the error of his ways and comes back to help.
You sure as hell got that in Empire, with Han captured and Luke physically and emotionally broken.
But in ROTJ, you never feel the danger. There was a great opportunity to feel this for Leia in the speeder chase, but then two seconds later - oh, she's fine, and hey, she's found a nice teddy bear friend!
The closest ROTJ comes to giving you a sense that a main character is in serious danger is when the Emperor is zapping Luke with his lightning. And it's all too short.
You never get the feeling that the rebels might lose. You never get the feeling that Lando could die destroying the Death Star. You never get the feeling that Han and Leia could be killed destroying the shield generator.
That's ROTJ's biggest problem. It's too safe.
Star Wars = 9/10
The Empire Strikes Back = 10/10
Return of the Jedi = 7/10
The Phantom Menace = 5/10
Attack of the Clones = 2/10
Revenge of the Sith = 3/10