Firefly was a brilliant little show; great acting by a stellar cast; great television-sized SfX; fun stories; and a "little guy against the 'MAN'" overarching story theme. I, as a Southern Partisan (viz: the War of Northern Invasion 1861-1865) really resonated with the fact that the Firefly protagonist (Mal) was a "Browncoat"/rebel and part of the losing side in a recent war for freedom in the galaxy. In the Firefly Universe the tyrant (not tyrant lincoln but a distinction without a difference) of EMPIRE kept sticking its lasers and space ships in where they didn't belong.
Likewise, the great opening theme song has a Southern, rural, infectious "don't tread on me" vibe and is performed well by Sonny Rhodes.
Firefly is the GREATEST show to ever get axed after only one shortened first season. The show was so good that every time an episode was aired, somewhere in Space Heaven, the young Robert E. Heinlein, (he of the space juveniles), E. E. "Doc" Smith, Edmund Hamilton, Jack Williamson, Edgar Rice Burroughs, and Gordon Dickson were grinning and nodding their heads.