Long story short, I would put the films in the same order as the OP except with Phantom Menace above Revenge of the Sith.
1. Empire Strikes Back - A lot of the better parts of Empire are similar to New Hope's positives, so I'll focus specifically on how this compares to New Hope in particular. First, I appreciate the slight change in how the empire was portrayed. Palpatine as a Dark Lord controlling things from behind a hologram is more menacing than the odd military coalition implied in New Hope. The removal of Luke from the evolving romance between Leia and Han Solo, along with the full movie's length to work with, helped that aspect feel more organic. The movie also did a great job of making the Empire seem powerful, with the heroes losing their base, being betrayed, getting frozen in carbonite, etc. Plus, the acting was a touch better. My only real complaint is that the AT-AT is the most ridiculous attack vehicle ever devised. Giant Camel Mechs are silly even by Star Fantasy standards.
2. New Hope - A bit simple in some places, but still holds more than enough complexities in the story and presentation to study for years on end. I love the scenery in this movie, probably even more than in Empire Strikes Back. And though the characters fell into archetypes, it allowed for a more complex movie. The finale worked as well as it did because we had the hero, his robot buddy, his mentor's advice, an antagonist, Han Solo coming to the rescue, Leia on the ground, and Biggs's recent death. That's a minimum of half a dozen named characters necessary for that scene to work, and it was pulled off brilliantly.
3. Return of the Jedi - I do not mind Ewoks. Honestly, I find those little bastards terriying, and thought their inclusion kept the Endor setting from becoming repetitive. We'd already seen lots of firefights between humans with advanced tech, so throwing in aliens using melee weapons and elaborate traps made for a good counterpiece to the lightsaber duel and space battle. My main beef with Return is probably the first half hour. Though I enjoy this part by itself, it barely feels like it belongs in the same movie as the remaining 3/4 of the film. Also, the ending featured a bit too much switching between action scenes for my liking, a problem repeated in Phantom Menace.
4. Phantom Menace - I hardly need to explain why this movie is not my favorite, so I'll just explain why it's as high as it is. First, I feel that Anakin Skywalker was oddly better here than in Episode 2 and 3. I'm not exactly a huge fan of child actors, but the terrible Anakin dialogue in the prequels were a much better fit for a naive but promising nine year old than a a brooding young adult. Things like podracing and the Gungan battle against the droids were a bit long or mishandled at points, but added something new to the series while feeling like a kind of action possible in this universe. Also, I feel that some of the Obi Wan and Qui Gon scenes worked well. Seeing them talking, moving around, and fighting, I could easily believe that these two had been on many long journies together. The prequels' fight scenes are often flash over substance, but here they at least help convince us that these two know each other really well. Ultimately, I feel Phantom Menace is the only satisfactory part of its trilogy. Where Episodes 2 and 3 failed to be compelling portions of the overall arc, Phantom Menace at least gave the setup well enough so that Anakin's fall was still tragic.
5. Revenge of the Sith - This film was not that great, but at least Palpatine had a fair amount of screen time. He made every scene he was in more interesting, and had some of the better bits of dialogue. Hayden Christrensen and Ewan McGregor were actually getting better at their roles as Anakin and Obi Wan respectively. In the scenes where they had less dialogue, they had some good scenes where they expressed a fair amount of emotion through body language and facial expressions. And if you just want the cool action scenes, this one has a few of those. So Revenge is more bad than good, but has redeeming qualities.
6. Attack of the Clones - I dislike this movie for a number of reasons, but here are a few outstanding failures. First, a lot of the film felt unnecessary. Obi-Wan's investigations were given lots of screen time that should have been devoted to making the Anakin/Padme romance more believable. I don't want to see that very much, but considering how Anakin is basically the focus of this trilogy, he needed that screen time. The same applies to Jango Fett, Mace Windu, and so on. The story did not need them. But the worst part is Anakin's actions after his mother dies halfway through the film. He kills a village of Tusken Raiders. From that point on, the trilogy is largely redundant because Anakin has become a Dark Lord in all but name. He is a killer of innocents who is somehow treated as a swell guy by his love interest and comrades. From that point onwards, it was impossible to care about him.
