zombie84 said:

The Ewoks are a big part of it, but there's much more to it than that. The plot is tired--another Death Star, another space battle and escaping a chain reaction, another stolen plan, and another cantina with more puppets. The dialog isn't as good as Empire either, and the character relationships are uninteresting, especially Han who goes through the motions and Leia who doesn't do a whole lot. Also, Leia being Luke's brother is infinitely stupid. Add in the Ewoks taking up almost 1/3 of the film and you've got a disappointment. It just doesn't have the originality and sense of urgency the other two did.

However, there's lots to love about the film. The Jabba sequence is fun, and the sail barge battle is right out of an Errol Flynn movie and is one of the most entertaining action scenes in the trilogy. The visual effects are jaw-dropping, probably the peak of pre-digital technology IMO, and of course you have a great John Williams score. But its just great to have the characters together again. You grow to love them over the past two films and its a small treat just to see them as an ensemble again, even if they are only briefly together. The Emperor adds a new twist to things, but the real standout is Luke Skywalker's story. Its very, very compelling stuff, especially with Vader, where they mainly talk instead of fight, which was much more interesting in some ways, and Mark Hamill really carries the film.

All in all, it's easy to see why people like this film the least. But that doesn't mean it's not likeable. It's frustrating that it wasn't as good as the others but they set the bar so high that this is still better than a lot of movies even when its the disappointment of the trilogy, and is a worthy piece of entertainment.

There. I couldn't put it better myself.