Kylo killing Snook. Thought this was done very very well. Especially when Snook says to Kylo to kill his "worst" enemy because let's face it, Kylo was basically a pin cushion for Snook. What proceeded after that moment of unity for Kylo and Rey was also really well done. I thought it was appropriate that Kylo had created this bond with Rey and Kylo gunna be Kylo and Rey gunna be Ray and the end up on different sides.
Stuff like "kill your worst enemy" was so freaking on the nose. It was already clear from the first movie that Kylo felt like a slave to Snoke and was regularly abused by the man, and here he just went and rubbed his nose in how stupid Kylo was (where Kylo thought HE was talking to Rey, and Snoke was like, "Yes, you foolish boy, it was me who made it work; I just used you." I mean, was it already not clear that Kylo needed to kill Snoke and hated Snoke on some level, as yet another father figure who pushed him down and didn't really give a shit about him? Did anyone in the audience think he would actually kill Rey, who he had a connection with? Or would he kill this scumbag mentor who was a real danger to both of them regardless of their alignment? It was kind of a ho-hum that he tried to kill him; it was kind of shocking only in that he succeeded with a silly trick like that and that after all the Snoke setup, the script just tosses him out with the trash abruptly.
I think I expected more nuance from Johnson because his other directing work has been more skillful. You don't need to telegraph a bunch of shit as if viewers are stupid. So much of this script felt like it was aimed at 12 year olds, with all the extraneous / non-organic humor, the superficial / on-the-nose dialogue, the little "p[uffin]-woks", the clumsy "luke as grumpy old get off my lawn" guy, the mostly lack of real tension.
When I see praise for this movie, it seems more about what people are layering into the film things their own feelings, versus what actually is there on the screen. Like, sure, Leia's "hope" is admirable, but I'm not looking for someone who is hopeful, I'm looking for characters who feel real (of which "hopeful" can play a part), and while she is one of the better characters in the film, her lines all felt canned and like I was reading an inspirational calendar. Just shut up already. Be a real character. They couldn't even let her die in peace but had to break the established rules by giving her powers as plot armor on a level never hinted at by any part of the story previously.
Or whassername telling Finn she loved him -- she doesn't even know him and she went straight from hero worship to thinking he was a scumbag traitor to now loving him... when the gravitas of the that final scene actually would have involved the writer allowing him to sacrifice himself. That would have given SOME weight to things even if it would have been a waste of the character considering how much buildup he got in the first movie and here he was kind of sidelined. Or is she dead now? I wasn't sure, but if she isn't... well, once again, a lack of realism and gravitas.
All I really ask for is some coherence in character arcs and prior episodes of the story, but... I'm not really sure what this was about. It's not like the ideas were bad, it's just the implementation that was truly lacking.
EDIT: Here's a decent rundown of some of the problems (I don't agree with ALL of the complaints but the huge majority are ones I had). There are some solutions offered, and they're generally pretty good; obviously there are various solutions to these problems, but these work.
http://www.looper.com/101437/last-jedi-even-better/