This thread seems like it needs yet another person stirring the pot with his view on the franchise. Here's my list.
** The Good **
V: Others have already explained the many reasons why TESB is the best.
VI: Ends the trilogy in the best way possible. The Ewoks aren't even that bad on a re-watch.
IV: It's cheesy but a classic for a reason. Had it not been the first, this movie would not be ranked so highly.
Rogue One: While the first couple acts have problems, the movie is enjoyable throughout and the Battle of Scarif is right up there with Endor.
III: Redeems the prequels. Anakin and Padme actually feel like a couple, and the plot is solid. And we finally see the Clone Wars in action.
VII: This took the universe in a direction I disagreed with, but I still loved TFA. It's a thrilling movie and introduces compelling new characters.
** The Bad **
I: Introducing Vader as an innocent child was a worse idea than Jar Jar. Ignoring that, this movie is at least enjoyable due to strong acting and visuals.
II: Anakin/Padme scenes make AOTC unbearable. Everything else is solid, though Dooku is a weak antagonist. I wish we had seen him in TPM so his turn to the dark side would mean something.
VIII: I have many problems with TLJ. Those problems have been discussed to death elsewhere. Hopefully Abrams can pull a ROTS with episode IX.