Based on that description it could have been a really dumb show, however it is extremely well written with fantastic and densely textured world-building and a tightly constructed plot. However, the real strength of Firefly is the characters, who are nuanced, interesting, realistic, and pretty entertaining. I was trying to find a short clip that sort of captured what was really great about this show, but I found I couldn't find just one, so instead here is one for every major character.
Mal (somewhat NSFW)
Kaylee
Wash
Jayne
Zoe
Simon
River
Shepard Book
Of course, the other great thing about Firefly is the whole aesthetic. It's this very bizarre, yet somehow coherent mash-up of Western, modern, chinoiserie, and Fifth-Element style futuristic that ends up with a Western Steampunk feel. This outfit is a version of that wearable for class and a day of running around. Of course Steampunk means brown and other earth-tones and I added some cowboy boots and a wide belt to give it a more Western feel. Eventually I will figure out how to mod this sure so it fits better.
Shirt: Tee Fury
Belt and tights: Torrid
Skirt: In the Starlight
Earrings: Target
Boots: ebay, by L.e.i.
I wore theme-appropriate makeup, specifically the eyeshadows from Geek Chic' Big Damn Heroes (Firefly themed) line, specifically: Inevitable Betrayal on the lower lid, Very Fine Hat as an eyeliner, and Captain Tightpants in the crease.