I've read a number of entries on Revenge of the Sith. For example, Rory wrote one.
There hasn't been that much written on the plot, however, so I thought I'd cover it here.
Padme is pregnant with twins, but she and Anikan wish to keep their children safe, so she gives birth on a backwater planet, and they then return to their duties. Anikan's training has gone well, but there is friction between him and some of the Jedi council, because of his impatience. He is dispatched with Yoda and Obi-wan to broker a cease-fire between separatists and the Republican forces.
Chancellor Palpatine is conference with a group of Senators. In an unmanned surveilance center, we see several Jedi creep up stealthily, overpower the guards, and place an explosive device. We switch to a different camera, and we see Palpatine get up and leave the room. The camera pans in close up across the 5 senators, and we see that the 5th one is Padme (aka Queen Amidala) just before the screen dissolves into static as the room shakes.
Cut to Anikan, Obi-Wan and Yoda. Anikan suddenly looks troubled, senses that Padme is in trouble. He boards his fighter and races back, arriving just as Padme dies. The Chancellor recruits Anakin to find the group that had planted the explosive, and sends him to a planet on the outskirts of the Republic.
Anikan arrives with the Republic forces to the location the Chancellor had sent them. The Republican forces take out the field generator, and Anikan takes out the guards. He reaches the command center and finds it manned by several members of the Jedi council, who admit to being behind the attack. Enraged, he kills all of them, when Obi-wan and Yoda arrive. They try to convince him to calm down, but unsuccessfully, and they begin a battle (with lots of "light side/dark side" discussion). They travel through corridors, and find Anikan's children playing in a large hanger. At that moment, the fusion reactor powering the site overloads, the roof of the hanger collapses, and Anakin uses the Force to protect his children, but he disappears under a pile of rubble.
Obi-wan and Yoda leave with the children.
We see the Chancellor in a medical center. In an operating theater, the last stages of the Vader-ification is taking place. Palpatine leans close and says, "Can you hear me?"
As the scene fades to black, over the famous breath sounds, we hear, "Yes, master".
No, wait, that's the kind of plot that somebody with no talent or screenwriting experience would come up with if he spent 30 minutes thinking about it.
I'm sure the real one is much better.