Firefly was a pretty cool series. Underpromoted and poorly scheduled, and therefore extinct, but very enjoyable.
There has been buzz for quite some time that Joss Whedon is capable of producing well-written, really good tv, but due to my allergy to all things Sarah, Michelle, and Gellar, I've never given myself an opportunity to confirm this perspective for myself.
Then a friend recommended Firefly, starring the guy I always thought of us "the off-brand Jason Bateman" (Nathan Fillion), and featuring a Babylon 5-looking spaceship (not to mention, honest to god, castoff Starship Trooper uniforms).
As it turns out, it's pretty good stuff. (And my sci-fi standards require me to turn my nose up at most extraterrestrial offerings of the entertainment variety.) An interesting mix of Western and Space Opera, with some nicely written relationships, and good humor. Too bad it never broke orbit.