>>215423058 (OP)
They're all bad in their own way.
TPM: Boring. Meaningless. The best thing you could say about it at the time is that the next movie could have retrospectively given it some kind of meaning, and it didn't by itself destroy the trilogy or franchise. If the next two had been good it would always just be remembered as the boring one.
AoTC: Failed to fix TPM and made matters worse introducing its own problems. Anakin was a whiny little shit, and the romance stuff was just bad. The Clone Wars felt small and stupid, not like you imaged it at all as history in the OT. Just disappointing and 'WTF are you even doing George?'
RoTS: Would have had to pull a rabbit out of a hat to fix the prior two, (I actually think Sith Lord Jar-Jar would have been the best angle actually). But like the Disney sequels at this point, too much damage has been done, and 90 minutes is realistically just not enough time to fix it.
You'd have to basically SHOW that Anakin is a great, likeable, especially skilled guy that makes his fall tragic
AND SHOW him and Obi-Wan are actual good friends instead of just telling us
AND fix the retarded romance shit with Padme
AND have a standalone exciting adventure plot because it's a fucking movie
AND have him tempted and fall to the Dark Side in an actual sensical human-relatable way
AND have him become Palpatine's little bitch-boy, (though maybe better if you just left that and hint at him becoming further corrupted and eventually becoming Darth Vader in-between movies)
AND have the Republic turn into the Empire in a sensical way, (to be fair there was time spent on this at least).
AND tie up all the lose ends and mesh it with the OT
Failed pretty badly on pretty much all counts.
They each had some good aspects, moments, and at least it was genuine Lucas-verse, that defenders will point to, but overall they sucked and went from plain unwatchable, to boring, to laughable, to stupid, to kinda interesting ideas, to kinda cool moments.