The best order (if you must include all of them) is 4, 5, 1, 2, 3, 6, and maybe the Clone Wars serieses between 2 and 3. That way you preserve most of the OT spoilers while still ending on a positive note in a single gothrough. Also, I don't know why more people aren't more annoyed about Jabba's random appearance in ANH than Greedo shooting first. Sure, it changes Han's character a bit (not entirely for the worse), but the Jabba thing just makes no freaking sense. It was just to show off that it was 1997 and they could do a CG Jabba, even though they really couldn't.