Best to worst, starting with the best:
The Empire Strikes Back - I think most people will agree here.
Star Wars (AKA a New Hope) - Still holds up pretty good.
Return of the Jedi - The weakest of the three, but still a really good movie. I don't hate the Ewoks that much.
The middleground:
The Force Awakens - This movie is surprisingly good, but would have been better if the next director would have actually followed up on JJ's plot threads, instead of throwing them aside. But we'll get to the Last Jedi in a moment. TFA has an amazing opening act and gets the tone of Star Wars right.
Solo a Star Wars story - It's a pity that this movie suffered from The Last Jedi's poor reception. It's a lot of fun from start to finish and has a pretty solid script. It is surprising it is as good as it is, given the production issues.
The Last Jedi - I had very mixed feelings about this movie, which have only dipped more and more into the negative after seeing it. The movie has one fight that is really good, and does some cool new stuff with the Force that is really interesting. It also thinks that having no plot resolution is a good twist, is completely tonedeaf when it comes to inserting its humor, and sets up a big end battle, only to then not have it happen. Oh, and there's also a whole lot of meandering at a casino planet that serves no purpose to the plot.
Revenge of the Sith - It has a great opening act, and that's about it. There is just so much cringe in this film. For many this movie may be a guilty pleasure. But it's not a good movie at all. It is the moldy candle on top of the turd-cake.
The bottom of the barrel:
Rogue One - An incoherent tonedeaf mess, sufficated by fanservice, and with no likable characters (or characters at all). Its worst crime is that there are no stakes... like, at all. Also, Darthvader is just thrown in because... Vader, and they manage to get his character wrong. But he has a lava castle now! Because who wouldn't want to live on top of lava, after having such fond memories of it?
The Phantom Menace - The real menace here are an annoying kid actor, and Jar Jar. Also known under its working title: How to suck the magic out of a mythology. This movie had many people in denial afterwards. Perhaps it was just a rough start, and the next film would course correct?
The Clone Wars - It helps if your lead is likeable. Also, George Lucas can't do romantic scenes to save his life, apparently. This movie's diabolical dialogue about sand will be parodied till the end of time. It also erased any hope that this trilogy would course correct.