I rented the movie Serenity a few weeks ago, because of a positive newspaper review, and I really liked it. I found out that it is based on a short lived (14 episodes, 2 of which never aired) Sci-Fi series called Firefly, that was on Fox for half a season on 2002.
I bought the boxed set, and I had to pace myself, so I wouldn't suck down all the episodes in two sittings, and run out of show. It was that good.
Firefly is a cross between a space opera and a western. It is about a captain, who is somewhat Hans Solo like, and his crew, as they do (mostly illegal) odd jobs under the noses of the smothering Alliance (think inter-planetary UN, with lots of corruption).
There are no aliens, and no faster-than-light spaceships. There are lots of steel guns that go bang. The writing is smart, and humorous. You have to pay attention to the dialogue, because the writers slip good jokes in frequently when you don't expect them. Compared to all the stale, predictable "reality-lite" TV shows, Firefly is fresh and different. Because the show isn't about intergalactic politics, high tech toys, or inter-dimensional portals, it focuses on the interactions of a smuggling ships crew.
It is so good that this boxed set of half a cancelled TV season is the #16 best selling DVD on Amazon.