The original series I considered to be rather nice because despite somewhat primitive mechanics at the time, it carries an old movie nostalgia to me that I've since pretty much considered character. Character to the plot, the setting, and the characters themselves. An air of mystery that turned out alright, some interesting individuals, [s]why the fuck do lightsabers not choose if they cause blood or not Ben what were you doing in that bar[/s], and then the occasional dumbass moment by the Empire in decision making. But those moments weren't prevalent, nor did they define the antagonists. And, while far weaker, that wouldn't define the protagonists either, beyond reason. The first death star's destruction takes a bit of rickety stretching, but is largely excusable to me. The guy's 25, a damn good pilot from childhood training, and just got some fun little force powers that he went 'hey, what happens if I angle those shots down'. I can accept it.

It's when the prequels come in that you start getting some really irksome continuity errors, character flaws, missed opportunities, shitty presentation, frequent moments of Lucas retardation that indicate he had no such input that may have been present in the original series, etc. Film by film. Perhaps you could make these cases for the original trilogy. I admit not having seen them in a while, so I can't point by point them as much.

Phantom Menace.
 - The Trade Federation is a huge entity presumably built by strong administrators and able commanders who've kept a planet under blockade (for some reason, I'm sure it's important) for a while. Their decisions at the beginning of the movie begin to take spectacular pitfalls that damage immersion for me. They blow up the Jedi ship first, successfully allowing the Jedi to know what's going on before making their next move. Then they filter obvious poison gas into a room where the alert Jedi are literally watching it come. Gross underestimation of a Jedi, OK, fine. Then the leader has a cluster of droids stand outside the locked door, and tell them to 'clean up what's left'. If you have that many droids prepared to clear out a room where the poison should have killed the jedi, then maybe you should have gotten better firepower involved, or just... leave the door closed for a few hours? Nope, just immediately open the door, let the jedi out to slaughter them, and then they speed off across the ship largely unchallenged and untracked from there. Underestimating them is one thing, and a mistake that should never be repeated by able officers, but not even putting a serious enough effort into putting them down begins to stretch it. And of course the order of operations (blow up the ship so the Jedi know something is wrong) is quite off.
 - Qui-Gon splits up the Jedi. What. Why. Here's some reasons why this is stupid: a) they could land clear across the world from each other, thereby splitting up and being almost independently useless for a while and b) his logic doesn't hold up, as it's easier to detect an intrusion in two ships [i]and[/i] put it down. I begin by questioning the judgement of  the Jedi Master, because I can't see how that's a viable plot. From Kenobi, sure, he's young and unskilled, but Qui-Gon?... okie
 - Naboo's blockade escape scene struck me as totally stupid. The protagonists later charge into the federation's totally dumb ring (...doesn't a planetary blockade cover the entire planet, not just a ring? whatever), straight into the core of fed firepower. That many ships attacking something that is coming right towards them should, by rights, instantly blow away a little ship. All they do is manage to hit the shield generator (why the bloody hell do you have shields if your generator just gets smacked? But then, why aren't you blown up in the meantime? Perpetual incompetence begins here). The little ship is basically unscathed and goes away. Goddammit. Sideous should fry every federation leader for that kind of idiocy, especially since he's the only antagonist I'd consider marginally smart by this point. Though the outcomes of some of his decisions to this point I'd question. Still, with a bit of expanded knowledge, I can excuse his hiccups with the fact that he's still an apprentice, I believe.
 - Later on, when the queen is captured, the fact that two droid-murdering jedi are loose doesn't convince the federation to put maybe a tiny bit of competent security around their most important package, the queen, when moving her to some obscure camp (...hmm.) This is where their idiocy becomes inexcusable for me. I can reluctantly stretch their handling in my first point as being underestimation by a group that doesn't fight Jedi. I can no longer stretch it to them totally underestimating the Jedi even when their most important captive on the planet is in their custody, with a Sith Lord bearing down on you to do things right. I begin to question how the Trade Federation even came together. Apparently anyone with foresight was murdered before the movie and Sideous took full control using total inerts. It could explain my less than forthcoming search for a concrete reason why the Federation would align with Sideous on a political level in the first place.
 - Presentation of the politics struck me as flat and has certainly earned many audience complaints. While I think the presentation was somewhat flat, like most of the dialogue across the prequels, I didn't have a true problem with this.
 - Anakin being born out of space magic and then the miticlilboboablubs. Eeeeh...
 - Anakin building C-3PO is really weird to me. I distinctly recall a junker C-3PO existing elsewhere that Anakin could have used. But even if that was not an option, I'm not sure why he would build a translator droid to help his mother. The droid's lack of real mobility across every movie and his general uselessness in anything practical leaves me wondering what the point of him is. Help me out. Does Anakin just not know what a real handy droid is? Is that all he can come up with based on seeing droids so far in his life? [s]Why is he a total Gary Sue in building and piloting at the age of 9? It doesn't even fit in later films, where I consider him to be relatively balanced?[/s] The droid then just poofs for a while and emerges complete by somebody somehow.
 - Maul's attack on the Jedi was poorly executed. Everyone was allowed to run along a sidepath, and all of those people probably would have gotten to their destination. Step 1 is to deprive them of that route somehow. The jedi are obviously a priority, but they are not the only one. And besides, surely involving a bunch of more regular people in a bloodbath would be more fun for him. [s]And result in a less total flashy scene and something to set one at the edge of their seats more often.[/s]
 - Space battle with Anakin. The equipment in the cockpit seems to fit a 9 year old just fine. He's a brilliant pilot despite never having piloted something like that ever before. He blows up a ship despite the lack of experience and gets out without a hitch. He's on par with Rey at this point. Yes, I'm going to slam Rey later.
 - Missed opportunities in having Kenobi show actual emotion instead of more flashy movey stuff that wasn't as engaging for me.
 - Kenobi could have been written a [i]little[/i] more enthusiastic when handling Anakin.
 - Dooku could have been lended more depth by being involved in the movie. Really, I think there was loads of missed development on his part, which I'll cover soon.
 - Gungan guy was marginally excusable for me. I can elaborate why if someone wants. But his army and the underwater kingdom stuff, now, that was pure cheese.

In Attack of the Clones, I have little to say about plot points, largely because I can barely remember it. I watched all 3 movies at about the same time, and Phantom Menace was at least more memorable to me than this one. That's because Attack of the Clones I think was the peak of flat presentation.
 - Dooku's presentation missed extreme possibilities. His change to the Sith cause, his loose connection with Kenobi to possibly tempt the younger Jedi Knight and give him an actual problem to face across the film at a personal level. I rather liked the character. I don't think he got enough credit or development based on my theories of Dooku.
 - Overall delivery was rather flat. The content [i]worked[/i] (not particularly engaging and remember, I don't even remember enough to nitpick every little thing anyways), but all in all, everything could have been more interesting.

Return of the Jedi I believe was the best production of the prequels, which in light of the above probably doesn't say much. It also both closed stories from the old movies and opened new holes that went straight into the original series. A few things that make the continuity of the prequels dubious as anything more than a retelling pieced together by rumor. I'll tie in events between the prequels and the original to start with.
 - Padme dies upon giving children. Did nobody remember that Leia had memories of her mother? Is Leia a super-magic baby who can remember one or two smiles off her dying mother and translate that into an implied early childhood? Don't answer that...
 - Kenobi later appears to totally forget two iconic droids owned by Anakin, with one literally built by Anakin (why didn't he at least send someone to figure out where they went? Did he just forget, too?).
 - noooooooooooooooooooooooooooooooooooooooooooooo
 - Minor flaws that you can probably find online sprung up all over the place thanks to the fast and loose continuity of Lucas
 - Palpatine is pretty generic. I was rather disappointed with his final presentation. He might have caught some of the badass elements, but I expected more from the figure based on his originals presentation.

As far as characters go, I think the prequels missed development on Dooku, Kenobi and Palpatine, and scenes to make others like Qui-Gon, Maul, and Padme a bit more relatable and fleshed out beyond single elements or otherwise underwhelming characters in their film presentations. The movies clearly suffered from back and forth decisions on backstory, and ROTS was a patchwork of endings that rather badly connected to the originals on the details. The story was very long, a bit glazed over, and in my opinion, pretty bad. The primary saving grace is action (when present), some interesting scenes, the brand and the a couple of interesting elements across the movies (yet, in my opinion, just not enough).

I redirect fire to the latest disney entries.
 - Foremost on my mind is Rey, a character who I believe is simply overpowered and a bad character given her presentation as compared to Luke and [i]later[/i] Anakin. She has little development, no real arcs that I'm aware of, succeeds relatively easily in things she attempts, only gets put to a stop when big bad [s]boring and underdeveloped big bad[/s] Snoke is involved, absurdly powerful in the force at first glance without a proper justification, and easily stands toe to toe with an edgy wannabe Vader who at least has training by a supposedly very competent dark lord of something who is called Snoke. Based on the information about her, I'll make comparisons to earlier antagonists. Original Luke I love as a character. He is natural, nicely balanced, and a character I'd willingly accept as a protagonist in a star wars roleplay were I to make something 1x1 as a GM. Anakin's first movie performance would be unacceptable in the same context, but I would accept the later two films. Rey I would accept in no form if a character sheet was compiled of what is known of her, as I don't think her story connects well with what she can do as presented. There's another movie I guess and still time to correct that. But after Anakin, I'm a little tired of the superpowered birth gimmick.
 - The First Order is lead by bungling idiots from the inept Ren to Snoke's supposed wisdom but semi-frequent failures (including his inglorious death that he somehow never saw coming) to just the officers who somehow made it that far.
 - The First Order's frequent idiocy is only matched by the Rebel Alliance's also incompetent command and decision making. Unlike earlier movies, it's not a matter of who's smarter. It's a matter of who's stupid enough to make the most fatal mistakes first.
 - I think Luke's character was butchered, outright. Improperly explained and simply unfitting to me.
 - I dislike the disney trilogy thus far for the same reasons why I dislike the prequels - presentation, character natures/development, and overall plots. Clearly, the movies fit the times, and the times are a bit scary to me considering how much dumbassery is prevalent in the disney movies (specifically targeting the new trilogy, I couldn't have been bothered to watch the other ones), the overpowered nature of the protagonist, the bullshit surrounding them that results in a comical galactic war between oldgen viewers and newgen viewers (in which I've been called everything for the most part, including a disney shill. Here's my obligatory disney shilling post, guys).

I've missed many things, bits and pieces are incoherent, etc. Long morning, what can I say. Felt like rambling.