Nemesis had some good parts but they are overshadowed by its mistakes.
TNG was an ensemble show and there were only a few minutes of the entire film where that ensemble feeling was there.
They changed Michael Dorn's voice, which made him sound waaaaaay wrong. As a life long Worf fan, the director massively blew that.
The Troi/Shinzon rape scene was not necessary, Shinzon's interactions with Troi just were awful. The deleted scene, ironically was the best of that.
I actually liked the Dunebuggy scene, I just would have preferred if it had taken place against proper adversaries.
I think that it's very possible that if Patrick Stewart had been Shinzon too, it would have been a great thing for the movie.
Data had to die in something massive, otherwise given how many times he had been repaired throughout the series, it just wouldn't work. I rather wish it had been something that challenged him. Flying across space to get to the Scimitar was cool but I don't think it really was difficult for him. I also didn't like the idea of him dying with a phaser in his hand. Data was such a calm and non-violent character, I think it would've been better and much more interesting if he threw himself into the Thaleron and it blew him up, taking the Scimitar with him.
Something that Into Darkness got right was showing the ship ready to go again after being repaired. We should have seen Riker take the Captain's chair on the Titan, we should have seen Picard and his new crew set forth into space again. Instead, they gave us the (hint, hint) that Worf is now the First Officer, and after the toast scene, we never saw Troi, Geordi, Worf or Crusher again. There's a lot of unforgivable fails in this movie, but that's a big one. The final sign off for those characters on screen should NOT have been in a scene like that.