For me, ROTJ really sucks. The Jabba scenes, the Ewoks, the Endor “battle”, the sister thing… Not to mention the poor direction (am I the only one to think that Richard Marquand was not a good director at all ?)

Not only does all this make the movie bad… but hey, it was the LAST episode, the conclusion: it was supposed to be the best movie of the trilogy, not the worst!
I was just a kid, and I remember how I was disappointed when I left the theater: the struggle of good against evil, the initiatory quest of the Force, the search for the father … all that ends with teddy bears, a bad dance group at Jabba’s house, Boba Fett that slips and dies just as “POOF”, and a hidden sister?

I’m not trying to compare the OT with the PT. But in terms of personal disappointment, ROTJ was much more disappointing for me - because I expected so much more.
16 years after that, TPM was not as disappointing for me. It was not up to expectations, but the dream was already broken long before…