5. A golden age of the expanded universe
There has been more material done during the Clone Wars era in the expanded universe than in any other time in the Star Wars mythos. There have been dozens of books, and a really excellent animated series in The Clone Wars. The quality of comic book series like Star Wars: Republic and spinoffs about the major background Jedi of the prequels really add a lot to the universe. Characters like Quinlan Vos and Aayla Secura were born of the expanded universe. None of these nuggets of awesomeness would exist without the prequels.