I didn't vote myself, as I don't really know which one I like least. I could make a valid argument for any in my bottom 3.
I: The whole story felt unneeded, in fact, some viewing orders recommend skipping this one entirely. Really bland characters that aren't that good, things like Jar Jar and Anakin blowing up a space station without any experience make this one kinda feel little kid oriented in some ways. Feels like a generic space movie for kids. Not really terrible, but not memorable either. Had it not been SW, 20 years later no one would even remember this one.
II: Characters like Dooku and Obi are better than the bland ones of episode 1, but on the other hand characters like Padme and Anakin are extremely weird, cringey, and annoying. Anakin comes off as a full blown stalker. You knew her for like a couple days 10 years ago, but you thought about her every day since? Kinda dumb. CGI is ugly, even at the time. Bad dialogue is prevalent throughout the whole movie. Also makes Boba Fett as a annoying little kid. Though the story is actually important, unlike 1.
The Last Jedi: Firstly, after JJ teased he hadn't revealed Rey's last name for a reason, everyone was theorizing like crazy. Then they come out and say both her parents AND Snoke are nothing? It's almost liked they TRIED to let people down. Next, I hated the direction of Luke Skywalker's character. He seemed like a mean selfish old man, very different from OT Luke. I was hoping for lots of cool scenes from him and thought he would become important and we could see a powerful, experienced jedi master in action. And then they kill him off, for seemingly no reason. Also, characters like Rose and Phasma are very annoying. Plot feels like a episode 5 copy. I will admit visually, it's mix of CGI and practical effects was gorgeous, but that's really the only really good thing about it. Lastly, it felt very feminist. All male characters were either lost and didn't know what they are doing, or morally compromised like Snoke, Kylo, and Luke. While female characters, like Rey, Leia, and Holdo are very wise and always know what they are doing. Yoda even goes as for as to say "Rey already has what she needs". I mean, she doesn't even need jedi training? Before you call me sexist, I liked Leia in OT a lot. Also, Rey never bothered me in 7, nor Jyn Erso in Rogue one.