These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
How exactly River's psychic abilities work is up to interpretation. The two most common theories are that either she's precognitive and can sense things before they happen, or that she possesses exceptional telepathic awareness of her surroundings which, coupled with her extreme intellect, lets her predict what's going to happen through analysis. Or maybe both at the same time.
Awesome Anachronistic Apparel: It is a space western... with T-Shirts, corporate logos, the occasional mongol raider-style hat and space hookers. Of course everyone looks awesome!
Better on DVD: Because you can watch the episodes in the right order, and without them being preempted by baseball games.
Bittersweet Ending / Distant Finale: The short story "Take the Sky," included in the Firefly: Still Flying companion book. Set 20 years after Serenity, whether it leans towards bitter or sweet depends on which character you focus on. Of course, there is always the chance that it all takes place in Mal's head in a split second before he faces the Operative for the final time, but it is ambiguous enough to speculate on. And there might be foreshadowing.
Freakin' Niska! This is a guy who had his wife's nephew tortured to death, and shows him off to the people he hires. Not a nice guy at all, especially in "War Stories" when he gets his hands on our Big Damn Heroes.
Crowning Music of Awesome: Firefly and Serenity both have decidedly awesome soundtracks composed by Greg Edmonson and David Newman, respectively. Special mention goes to "Mal Fights Niska / Back Home" from "War Stories", and "Reavers Chase Serenity" from the pilot.
Not to mention the end credits for Serenity, the tail end of which features an instrumental Theme Tune Cameo for Firefly.
Ear Worm: The title theme is the first example listed under Live-Action TV on that page for a reason. Also frequently mentioned are the Fruity Oaty Bars jingle and the Ballad Of Jayne Cobb.
Ensemble Darkhorse: River, who went from being a secondary character — who still had quite a bit of focus on in the main series — to being one of the two leads in The Movie. She's on the TV Tropes Wiki Drinking Game for a reason. It's also telling that her entry on the character page is twice as long as the others.
Evil is Cool: Averted. Dr. Matthias is a banal and rather boring person. The sort of person who would be running a government brainwashing project in other words.
Fan Preferred Pairing: There are three main, widely accepted pairings for this show: Mal/Inara, Simon/Kaylee, and River/Jayne. Simon/Kaylee, however, while running on UST for the entire series, was made canon at the end of the movie, and Mal/Inara probably would have produced some sort of result anyway if the show had gone on longer - so River/Jayne, which is only hinted at in the show, is the only real example of this trope portrayed here.
Foe Yay: Mal and Saffron have heaps of this, as do the Tam siblings with Jayne.
Ho Yay: According to Adam Baldwin, there would have been deliberate Ho Yay between Simon and Jayne if the series had not been cancelled.
Sean Maher also stated in a convention interview that he believed Simon had a crush on Jayne, something that would likely have been used in a future storyline.
There's also noticeable Les Yay between Kaylee and Inara and Kaylee and River, with the latter especially noticeable in the pilot and "Objects In Space."
I Am Not Shazam: Firefly is the name of the class of ship, not the ship itself. Serenity is the name of the ship, the first(ish) episode and The Movie.
And as Inara points out, it's not The Serenity, it's just Serenity.
Jayne comes very close to crossing it in "Ariel" when he tries to sell Simon and River to the Feds. He comes within seconds of getting Thrown Out The Airlock, but his regret and shame afterwards show that he is not completely irredeemable.
Niska crosses it when he kidnaps Mal and Wash and starts torturing them to death. Bad move.
Alternately, the point where Zoe jumps the gun on his Sadistic Choice and he responds by giving her "small refund".
"Heart of Gold". Rance. Willing to take out the entire brothel just to get to his kid, and is willing to be sexually serviced in public, because he thinks that's what women are for. Rather telling for someone who doesn't even survive the ep.
Saved by the Fans: Resurrected for full length movie by a dedicated fanbase.
Sadly averted, however, when it came to reviving the series as a whole. An attempt was made to buy the rights, but it failed without support from Joss Whedon or Nathan Fillion.
Selfish Evil: Discussed Trope. When Saffron heads the plot to steal the Lassiter in Trash, half the crew basically ask "Why is the selfish, conniving bitch who tried to kill us, who betrays everybody for her own personal gain here?" The other half have expressions that say they're thinking the same thing.
Spiritual Successor: Whedon's script for Alien 4 involved an amoral crew of mercenaries and a partially insane woman, subject of mysterious scientific experiments as part of a government weapons project, with preternatural abilities. Sound familiar?
What an Idiot: The guy who just beat you up and defeated your gang of mooks offers to give you back all the money owed to your boss and let you go, no hard feelings. Do you A) gratefully accept the unexpected mercy, or B) threaten to hunt down and murder the man while standing between him and his rotating engine intake?
What Do You Mean, It's Not Political?: People seem to want to read politics into Firefly everywhere, with critics interpreting it as everything from an anti-Big-Government libertarian parable, to a racist, pro-Confederate perspective on the Wild West. The show is, in fact, fairly apolitical; with the exception of some possible feminist overtones (which are typical of Joss Whedon's work), Firefly does not seem to have one specific political "message" as much as people would like to believe. Whedon even qualifies that, if anti-government messages do sneak in, that is because the story is essentially Mal's story, and it all comes from his perspective as a bitter ex-soldier who fought against the big bad government.
The premise did come from journals of Confederate soldiers in the frontier. Whedon wanted to make a series based on the losers of a Civil War.
Stoic Woobie: Simon has to deal with pretty much everything his sister is going through, and received little to no support from either of his parents when he made his move to get her out of there.
