But there are other reasons I love it too -- idiosyncratic reasons. These aren't the reasons I'd push it on anyone. They're just small things or particular twists that add to my particular love for it. Without the wonderful writing, acting, characters and stories, they wouldn't mean anything. But on top of a great show, they're a marvelous garnish.
Some of them are more substantial, some less. I'd hoped to start with some of the more substantial ones -- but I think I won't get around to it before Serenity opens. So instead I'll start with a minor, but extremely delicious, reason I life Firefly: the Chinese.
The future history of Firefly imagines that the U.S. and China formed an alliance and colonized space. Thus the future is bilingual -- including all nine of the main characters, no matter how little education they have ("If I wanted schooling, I'd have gone to school.") Chinese writing is all over -- signs, the name of the ship, art in the captain's cabin. A danger message the ship broadcasts in one episode is given in both English and Chinese. It's not that a big deal is made of it; the world created by this alliance is simply bilingual -- being bilingual is just standard in the culture (which is historically quite reasonable, actually: many cultures have had a wide degree of bilingual; America's monolingual nature is arguably the exception rather than the rule).
And the characters speak Chinese -- regularly, in the show. This Chinese tends to be phrases that the viewer can not understand without any interruption of understanding (it's not subtitled) -- thus the most frequent uses are curses, ranging from the simple (哎呀, "damn") to the absurd (大象爆炸式的拉肚子, "the explosive diarrhea of an elephant"). Besides these, the Chinese phrases are things like "thank you" (谢谢) or "little sister" (妹妹) -- stuff you can easily 明白 from context, even if you don't know a single word of Chinese. (Though if you're curious, all the Chinese used in Firefly, visual and oral, is translated here.)
Now, since none of the actors really spoke Chinese, they speak it pretty badly -- even I can hear that sometimes, and I don't speak a word of Chinese! (Well, one word: 谢谢.) It's possible that anyone who actually knew Chinese would be driven crazy by this -- possibly even to the point of finding the show unwatchable. Though certainly some fans of the show on the net know Chinese; but then, those who hated it and turned it off are unlikely to hang out on Firefly sites! (Strangely enough, though, in the Serenity comics (a three-part series comprising a single story which takes place in the six-month gap between the final episode of Firefly and the start of the film Serenity) the characters appear to speak it perfectly. The benefits of having letterers do it rather than actors, I suppose!)
The show also, to its credit, tries to mix a Chinese aesthetic with a western one ("western" in two senses: broadly in the sense of Western Civilization, but specifically in the sense of the old U.S. West, as the show is envisioned as a space western (a notion which, before I'd watched it, turned me off -- it seemed utterly silly, the sort of thing mocked decades ago in print SF -- but which Whedon makes work very well.)) This is noticeable in the visuals of the show -- costumes and sets -- as well as the show's music, for example. The show tries to be deeply bicultural, albeit extrapolated into the future and mixed with other things as well. And it does pretty well, I think.
But what I love is the use of the language. It's spread to Firefly fandom, unsurprisingly, so that (e.g.) the Firefly podcast, The Signal, has a regular feature "How to Speak Chinese" translating bits of Chinese used on the show. The advertisements for Serenity all have Chinese in them, so I'm hopeful that this will not get discarded in the film (although none of the snipets of dialogue from the trailer have any Chinese in them -- but I'm betting that they thought this would scare off audiences and omitted these deliberately.)
Why do I like this? Well, I'm a language geek, who -- despite an utter lack of any aptitude for them -- loves languages. And in particular I've for some time been fascinated and enticed by Chinese. I think the script is beautiful, the language fascinating and wonderful -- and likely to be increasingly important. So while, as a language geek, I'd probably think it was neat to have any language routinely used in the show (for instance, I always liked that Red Dwarf takes place on a bilingual ship which uses English and Esperanto -- although that's all in background signs; the characters don't generally speak it, although in one episode one tries to learn some, with hilarious results), the fact that Firefly uses Chinese in particular just warms my heart. I just love it. I like when the characters use it; I like seeing it in the background. I like having an excuse to learn little scraps of the language. I like the idea of a bilingual future, and that it's an English/Chinese one. I like seeing Chinese on Firefly websites, using it on message boards and in emails to Firefly fans without an additional excuse. I've loved having an excuse to include some Chinese in one of my posts on this website. It's just cool -- and one of the other reasons that I love Firefly.