Nathan Fillion) is often touted on the web as being a truer Han Solo than even Harrison Ford could must in the holy trilogy. A lot of this stems from memes about how Mal would shoot first (he would) unlike the weak ret-conning of Han waiting for Greedo to shoot first. So what?
I agree that Mal is a badass, but then again, if that's where it ended, he would be about as memorable as a 90's comic book anti-hero, which is to say not at all. Mal, at his core, is an indefatigable do-gooder. The man can't be helped, even though his crew is almost always down on their luck and the ship is constantly in need of repair, he goes out of his way to be a force for decency and "what's right" in the 'verse. Sure he'd like to get paid, but he's not holding payment over the heads of the people he helps.
Adam Baldwin). Jayne's the shows pure mercenary character who's out for money and big guns. He always asks how they're getting paid and is only ever interested in what his stake or percentage is going to be. He also loves the ladies. Jayne's loyalty is sketchy at best, and when asked why he's bringing grenades to a peaceful exchange of illegal goods, he asks why not. Jayne carries more guns than bullets so he's ready for any situation that could come up.
These two characters sound familiar? You GM enough games (usually just one is enough), and you'll see that Mal and Jayne can pretty much describe every player character out there. They are, in essence, representatives of Chaotic Good and Chaotic Neutral alignments. CCG players have terms for different kinds of players. I know Magic has their own, but I'm most familiar with Game of Thrones. In Game of Thrones, you had, for example, Shagga's or players who loved weird new toys they could mess around with without being terribly concerned whether they win or lose. I'm tempted to start referring to player characters as Mal's or Jayne's.
Looking at my Dragon Age game, I've got a Mal, two Jayne's, and a Mal/Jayne hybrid. Keegan (who invented this modern wonder of tabletop gaming), is playing a fighter seeking to become a Templar. He constantly seeks out ways he can help others, and was very excited last night when he earned the title "Mythal-Bane" as a sign for his commitment to seek peace and avert conflict before it can rise to the level of blood feud. He's committed to protecting the weak and helping the helpless (which shares a lot with another Joss Whedon creation now that I think about it). Chuck and Mike are playing my Jayne's, although they're both exemplifying different aspects. Chuck's mage is seeking ultimate power and any mystical items he finds along the way are only their to serve him in this pursuit. Mike's dwarven rogue is out to get rich and eventually open his own merchandise shops all over Fereldun. Keith is playing the hybrid archetype. His mage seeks power through a better understanding of the Fade while working closely with Keegan's fighter to try to do some good along the way.
moral compass here, that they ain't. Now this was their first adventure (which we just completed last night quite successful - write-up is coming soon), so it'll be interesting to see how this dynamic plays out. Given popular fiction, the prediction is that Keegan's character will naturally rise to the role of leader. After all, most Mal's in stories are de facto leader given that they can drive the story in a satisfying direction. They're also less malleable when it comes to what they can allow happen in from of them. It's not like their paladins that will not allow the group to torture a prisoner - a little torture can do a world of good in the world of fiction - but they can't exactly ignore a burning building full of orphans.
I'm sure there will be exceptions to this two archetypes, after all, Keiths' mage is a bit more nuanced when it comes to his motivations, but I think it's safe to say that in my experience (including my own characters), the Mal and Jayne archetypes are just more fun to play in general. Fun equals ubiquity. Hence, you see these types all over tarnation.