I've never seen Dredd or the Star Trek movie
Well, since those are among my favourites I'm obviously going to recommend them. :P
Star Trek is among the few franchises that I mostly like as a whole and geeked about it a lot, so I don't know how viable it would be for you. It has good action along with a pretty damn smart antagonist who has good motivation and background. The movie is not a sequel in a series, by the way. It's more of a follow-up to one episode that I don't think is necessary to enjoy the movie.
Dredd is a movie that I shouldn't talk about because no-one likes a fanboy gushing praises all around. I'll just say that it's a very tightly made action movie with good visuals and character development.