Never came across a single definitive list, so I thought I would make one myself.
The Phantom Menace
-When the Jedi, Queen Amidala and Anakin arrive on Coruscant, Qui-Gon states that ‘the situation has become much more complicated’, there is an optical wipe to an establishing shot of Senator Palpatine’s quarters. It then cuts to the interior.
-In his first scene, Sebulba’s subtitles are changed to remove “Skywalker", since Sebulba doesn’t actually say Anakin’s last name in the scene.
-Several introductions of other racers are included.
-A shot of Watto cheering Sebulba is removed.
-Shots of the podracers starting were added.
-The podrace scene is extended, with more footage during the second lap: A shot of a tradesman in the stands, Anakin outwitting his rival Gasgano, Anakin repairing his racer after an engine detaches, and a reaction shot of a racer before he crashes.
-After Qui-Gon’s line, there is a new scene in which Padmé, Anakin and Jar Jar board an air taxi. The taxi’s journey allows for an extended view of the Coruscant cityscape before the wipe to Palpatine’s quarters. The establishing shot of Senator Palpatine’s quarters is omitted, with an optical wipe at the end of the air taxi sequence to the inside of the building. The shot with Jar Jar and Ani at the beginning of the scene is also shortened.
-Orn Free Taa’s aides have been replaced by Twi’leks.
-A bridge is added to a shot of the Naboo landscape.
-Pink tints appear during certain scenes.
-The opening crawl was re-composited against the starfield.
-A new blurring effect is used when Obi-Wan Kenobi and Qui-Gon Jinn use Force Speed to escape the droidekas. This new effect is also visible as the Jedi run down the corridor in the next shot.
-When Nute Gunray and Rune Haako are observing the droideka on a viewscreen as they pursue the Jedi, the shot looks very different. It’s no longer a close-up, but a wide shot. It also features a new digital effect for the screen itself.
-An error that causes Fode and Beed’s hand to clip through their clothing has been fixed.
-Right after Jabba the Hutt’s introduction before the podrace a new voice is heard from a spectator when the camera is focused on the crowd.
-In the scene where Qui-Gon and Obi-Wan discuss Anakin Skywalker’s fate on Coruscant, the sun was brightened from orange to white.
-Calls from the Senate to “Vote now!” when Queen Amidala puts forward a motion of no confidence have been replaced with the sound of a general uproar.
-The Yoda puppet has been replaced with CGI.
-The pink tints have been corrected.
-The scene composition affected by image magnification in the original DVD release was restored bringing around 8% more picture to the frame.
Attack of the Clones
-Anakin and Padme do not hold hands.
-Anakin and Padme hold hands.
IMAX Cutdown Version
-20+ minutes are cut. Cut scenes include:
The Jedi Council meeting with Palpatine after the first assassination attempt
Obi-Wan in the Jedi Archives
Anakin complaining about Obi-Wan’s mentorship skills to Padme
Padme and Anakin meet with Queen Jamillia on Naboo.
The meadow picnic scene
Anakin riding on a shaak
Dooku speaking with Obi-Wan while Obi-Wan is being held prisoner on Geonosis
Anakin and Obi-Wan’s initial meeting with Padme
Bail Organa’s lines are all removed.
-The closing credits are played in a slide-show format rather than the traditional upward scroll.
-Extra speeders are removed in the scene where Obi-Wan catches the lightsaber.
-The scene with Anakin’s confession to Padme about the Tusken slaughter is extended, and the music has been looped to accommodate the footage.
-During Mace Windu and Jango Fett’s fight, additional smoke and sparks were added to Jango’s jetpack.
-Padme’s “Yes” is changed to a more natural “Uh-huh” after falling out of the Republic Gunship.
-Shmi’s voice is added into Anakin’s nightmare, calling to Anakin for help.
-During the speeder chase, when Anakin and Obi-Wan pass through the damaged power coupling, several shots are rearranged.
-Dooku’s escape scene is re-edited, which created an irregularity in background music.
-There is a new color grade.
Revenge of the Sith
-In the scene where Obi-Wan has just left Mustafar aboard Padmé’s skiff, there is an optical wipe to a shot of Vader clawing his way up the bank of a river of molten lava.
-The wipe in the Mustafar scene is changed to a hard cut.
-At the end of the scene where Darth Vader is created, there is a different wipe.
-The scene in which the Clone Army arrives on Utapau is altered, adding dialogue from the troopers as they land on platform.
-The Kashyyyk headquarters rooftop was rendered to appear more significantly aged by adding moss and rust.
-The wipe in the Mustafar scene has been restored.
If there is anything that needs correcting/added, feel free to bring it up.