TheBoost said:
Considering that AOTC is a love story and ROTS is mostly a character study of Anakin, the 'movie serial' thing doesn't seem to apply.

100% agree. The whole PT is a character study about how a man turns to the dark side, so that negates 'the serial' right there!

Star Wars '77 is a serial because you don't have this huge character study, you meet the characters, you get to know the characters, but it is just enough to keep you invested. Same with Raiders, you get to know Indy, but not too much where it becomes some character piece.