I just went with my friend Scott to see the movie 'Serenity' today. We both liked it quite a bit. It has all the fundamentals of a very good movie: solid cast and characters that are likable and (somewhat) more than two-dimensional, a storyline that can be used as a metaphor for present times will still serving up a good adventure without being heavy-handed, and a fast yet not frenzied pace that never lags while still providing enough moments to get to know the characters better. There's also plenty of eye-candy (both special effects and people-wise) to keep everyone happy.
It shows vividly how bloated and tiresome the Star Wars movies became over time. Sometimes Serenity gets more across effectively in one minute than SW would in 15. For example, at one point after the heroes have escaped a pursuing fleet of ships, the movie briefly cuts to the commander of that armada asking some underling "What do you mean, disappeared?!?". That's it, end of scene. It tells us all we need to know in a concise and amusing way.
Let's just say I immediately ordered the complete DVD collection for 'Firefly' (the cancelled TV series whose setting the movie is based in) upon getting home. I'm really looking forward to watching the series, which those who've seen both say is even better than the movie.