Episode 1:

Anakin would be older and there would be no medichlorines.

Episode II:

re-write the love scenes,

Make it so that the clones were made BY THE REPUBLIC and not a SITH so that Yoda's decision to use them wouldn't be so assinine.

Episode III:

Anakin, once he pledges himself to Palpatine, is sent after the most powerful Jedi to kill, and not to the Temple to slaughter defenseless children in cold blood.

Padme would not die, and Kiera Knightley would reprise her role as Sabe in order to fake Padme's death.

the last part of the film would focus on Padme struggling with having to give up Luke and facing the prospect of being a single mother constantly on the run.