Below are video clips that I found on the FANPOP website, featuring bloopers in all three films in the STAR WARS Prequel Trilogy:
"STAR WARS" Prequel Trilogy Bloopers Video Clips
"Episode I: The Phantom Menace" (1999)
"Episode II: Attack of the Clones" (2002)
"Episode III: Revenge of the Sith" (2005)