The last of the "old school" Star Trek movies, Star Trek: Nemesis had the misfortune of following the least liked film of that franchise so it was either going to confirm that Insurrection was no accident and the Picard crew had really gone as far as they could or completely the opposite.
And although critics and audiences had nothing too positive to say about Nemesis and the film ended the Star Trek franchise promptly, never even giving the Voyager, Deep Space Nine or Enterprise crews a chance to make it on the big screen, for me Nemesis did exactly what it set out to do and delivered something as good as First Contact, if not better. Now I won't pretend that Nemesis doesn't have its problems, every Star Trek movie does. For one thing, Tom Hardy's villain, a young Romulan-made Picard clone, is a bit more cartoonish than he probably should be and looks nothing like Patrick Stewart. He's not bad, it's a decent, very entertaining performance, it's just that making him a Picard clone feels a bit too random and is a bit too distracting to truly have an impact. Also, this movie looks about as low budget as Insurrection did, not quite matching First Contact's great-looking visuals. Weird filters are used to make us feel like we're in an alien location at one point but they're not fooling anyone, the CGI really does stand out as much less impressive than it should be or used to be.
Be that as it may, I would say that Nemesis is actually one of the most underrated Star Trek films out there.
Because effort, that's why.
Whereas Insurrection seemed a little too comfortable with itself and therefore didn't really seem like it was genuinely trying, Nemesis makes a noticeable effort to do something different, darker, more in the spirit of First Contact but still unique. Nemesis looks like it has learned from predecessors' mistakes and is trying to do better. For one thing, Data's subplot actually matters, not only that but Data himself matters this time around! In fact, Nemesis contains the single most badass Data moment in any of the movies. In order to save Picard's life, Data not only goes to his rescue but jumps out of the Enterprise and flies through space from one ship to another and it is simply awesome. Picard finally stops being morally and politically grey and crashes the Enterprise into an enemy ship, another kickass moment. And in the end you do feel for these characters and although its mini-twist can be seen a mile away, it still somehow works! Kinda like that villain reveal in The Undiscovered Country. The film leaves you with a feeling that, indeed, these characters do care for each other and have come a long way.
Overall, Nemesis surpasses Insurrection in that real effort went into it and although it's not quite as slick as First Contact, it has a little more heart and is a little bit more memorable. What it lacks in production values it makes up for in drive.
Lots of action, lots of cool stuff: not perfect but well worth checking out.