Last Jedi is easily the best of the three (I recently rewatched TFA, and was surprised how poorly it held up considering I was rather fond of it initially.) That said, I honestly really don't like the whole casino side-mission or the attempted coup plot.
To clarify; it's all good work taken in isolation. The actors all did fine jobs, production design, etc. all excellent as usual. My criticisms are solely on the conceptual level. If it was a season of TV instead of a 2hr movie, I'd be fine with either development (in the abstract, at least.)
But in the context in which they're presented it just feels like they realised that they had no idea what to do with everyone but Rey & Kylo, and just created busy work for Finn & Poe. What's worse is they they also split the main cast into *three* separate plots, two of which were dead-ends. It seems crazy to me that they un-killed Poe in the last movie because Issac & Boyega had such great chemistry, then in the next one they separate them because their chemistry is too good? Pick a lane already! I mean seriously if they can't think of a good plot that doesn't hinge on direct personal conflict between all the main characters then that's a problem with the writing, not the characters.
It feels strange to have such fundamental problems with basically two thirds of a movie I actually rather like, but I guess that's a testament to how haphazard and incoherent the ST was as a whole.