Well, enough Star Wars bashing.
Let's move on to Marvel.

Spider-man 3 should have been two movies. It's only really bad during the last portion. It's like Raimi thought, "Crap, this movie is too long and we need an ending. Let's just have the two villains magically find each other and decide to have a big fight."
It should have ended with Spider-man defeating Sandman with symbiote and then the creation of Venom.

I saw Phantom Menace when I was all of seven, having seen the other 3 between 6 and 7. Even then, I detested Jar Jar (some of the Gungans were decent, but Jar Jar was awful) and had no problem with the Ewoks.

Venom as the big villain of the trilogy could have been really interesting if approached properly. That would involve skipping the origin story, though.

But the 'Venom-influence' was just awkward to watch, and not even in a funny way.

I'm gonna have to disagree with you on that one. HARD. Watching him walking around acting like he was hot shit and everyone knew it when, in fact, everybody was obviously repulsed by him was the high point of that movie.

I hinted at what I thought was the worst part of TPM earlier, but I might as well outright state it.

It wasn't the Gungans.
It wasn't the Chariot Pod race sequence.
It wasn't the other racist stereotype aliens.

It can be summed up in one word: Midichlorians.

The one scene, entirely unnecessary to the films and destroying the awesomeness of Jedi forever, was when Anakin has a blood sample taken and is shown to have an unusually high concentration of bacterium that are explained to give people influence over the force.

In this one scene, in this one snippet of exposition, he took what was essentially space sorcery with a heavy influence of Zen-Buddhism and despoiled it into a kind of reversed Scientology.

And it was not needed. It looked to me like Lucas fixing a problem because he had forgotten the rules of his own mythos. He needed some way for Qui-Gon and Obi-Wan to recognize that Anakin could become a powerful Jedi, so they went with this blood scanner thing, when really all he had to do is have the first scene with Anakin meeting the Jedi include the two Jedi looking at him with surprise and going:

Qui-Gon: Do you feel that?
Obi-Wan: Yes, a very strong disturbance in The Force.
Qui-Gon: It seems to be centered on this small boy.
Obi-Wan: So it does. We must take him back to the council, so he might be trained.

That's it! That's all that was needed! It was established in ANH that people connected to The Force can sense one another's influence upon it. Obi-Wan and Darth Vader tracked each other through a maze of a battle station to duel by feeling each other's Force presence. If Anakin was that strong in the Force, meeting him the first time would be like a psychic bitchslap to anyone with Jedi or Sith training. It'd be like a recording artist talent scout finding a six year old that could belt an A above high C.