I'll bite.
Reynolds, as in captain of Serenity.
Yeah, we are not talking about who has a better ship. But what I'm bringing up are two points.
1. Bare Knuckles Fight, anything goes. Who wins?
Honestly, I think both Mal and Jim are equally dirty fighters when it gets down to sheer survival. Kirk might have an edge due to training in hand-to-hand, which I never got the sense Mal had. But Mal can be clever in the midst of a fight - I have to say it's a draw.
2. Could Kirk captain the Serenity better than Reynold and could Reynold captain the Enterprise better than Kirk?
Mal wouldn't last 2 minutes in Starfleet - much too regimented, even in the wild and woolly days of the 23rd century. He'd hate it, they'd hate him and he'd walk. On the same score, I think Kirk, for all his reputation as a rebel isn't enough of a rebel to essentially be a scavenging pirate. That is, he's good at being a rebel within the highly structured environment of Starfleet. Unless, like Mal, he'd gone through some life-changing trauma. And that's the key to the whole thing. Mal kinda is Kirk - after he's lost all hope and has nothing to cling to except personal freedom. But that's such a significant character change that they couldn't swap places.
Personally, I didn't grow up idolizing Kirk so I vote Reynolds all the way. It'd be a much closer call if we replace Kirk with either Picard or Sisko.
It's not about idolizing Kirk, but about understanding the characters. Mal wouldn't do any better on board the Enterprise-D or E, or DS9 for that matter. Starfleet is the antithesis of everything he believes in by the time we encounter him in the
Firefly stories. And he's much closer in fundamental nature to Kirk than to Picard or Sisko. Picard's a pretty by the book sort of guy, highly principled and uncompromising. Mal will compromise principles in an instant to survive. Sisko's got a bit of rebel in him - but he's a father, which gives him a groundedness and conservatism that even Picard and Kirk don't have, so it ends up being less a bit of rebel and more a streak of stubornness. Look at how long it took him to accept his position as Emissary (that alone would send Mal running, screaming for the hills), and how, once he did, he quietly but firmly resisted Starfleet's efforts to control how he played that role.
Only if this song plays in the background will I watch this battle of fisticuffs.
http://www.youtube.com/watch?v=3Rl46Dpy-P4
Well - yeah, that kinda goes without saying, doesn't it?