Firefly was a Josh Whedon creation (the same guy that did Buffy the Vampire Slayer and directed the Avengers movies). The show combined elements of westerns with science fiction. It included actors like Nathan Fillion, Gina Torres, Alan Tudyk, Morena Baccarin, Adam Baldwin, Summer Glau, and Ron Glass as Preacher (one of my favorite characters). The cast worked exceptionally well together. The show only lasted one season, but it did get a movie several years later. The movie, called Serenity, provides a continuation of the original show.
Some fun quotes from the show.