Which is better:
It goes without saying that pirates have a lot of things going for them. They get to wear nifty hats, keep parrots as pets, and say things like "savvy." Ninjas, on the other hand, tend to wear all black with masks that conceal everything but their eyes. First of all, that's gotta be sweaty. Second, isn't all black a fashion faux pas, except at very specific times of the year? And finally, I bet it's harder to see in those masks than people think. Clear winner here: pirates.
So what about movies? Until recently, this category would have been easily swept by the ninjas. "Karate Kid" alone would have been enough, and despite the bad acting, there are some pretty sweet Jackie Chan movies out there. I know you're all thinking now, "Come on, those aren't ninja movies." True, they're martial arts in general, but they're close enough to count, and let's face it: the majority of Americans can't tell the difference between kung fu and feng shui. However, the recent release of "The Pirates of the Caribbean" series certainly evens the score in this category somewhat. I'm just not sure it's enough to topple the overwhelming quantity of, if not good, at least entertaining "ninja" movies. And I should really be deducting points from pirates for that terrible "Sinbad the pirate" series that was on TV 5 or 10 years ago. Winner: Ninjas.
Next category: moral/ethical code. Pirates, at least, have a code, even if it's only in regard to other pirates. Beyond that, however, they loot, pillage, murder, and generally speaking, defile the English language (at least, English speaking pirates do). Ninjas are killers too, of course, but at least they generally do it for money and not just for fun. I'm gonna have to go with ninjas as the winner here, but only by a hair.
Hygiene: I don't think anyone has ever seen a ninja without his guise on to be able to tell, but the fact that their assailants don't smell them coming suggests that they keep themselves in pretty good order. Whereas pirates don't even know what soap is. Winner: ninjas.
Final category: which would a kid rather be? I've never heard of anyone, kid or otherwise, playing pirate, but since every child raised in the 80's wanted to be one (or more) of the Teenage Mutant Ninja Turtles, and every child raised in the 90's wanted to be one of the Power Rangers, I am forced, again, to go with ninjas.
The final score stands thus: Pirates 1, Ninjas 4
Who would win in a fight:
It's tempting to give the edge to pirates right off the bat, since they fight with guns (and in the case of Davie Jones, giant boat-consuming squids), whereas ninjas fight with swords, throwing stars, and origami swans. However, this long range advantage is quickly negated when you consider the fact that 1) ninjas cannot be killed with bullets; they are invulnerable to them, and 2) ninjas are invisible, and 3) ninjas are quick enough to cleave a bullet in two with as little as a playing card and 4) they can dissect a 9th grade biology project from 500 feet away with their throwing stars. Advantage: ninjas.
In close combat, however, the advantage would seem to go to the ninjas, whose hand to hand fighting skills and short range bladed weapons are legend. However, keep in mind the poor hygiene of pirates. I believe that pirate stink is probably the only viable toxin to ninjas. Thus are there lightening fast reflexes and appalling flexibility rendered useless. Advantage: pirates.
In a deadlock as we are, perhaps we should consider allies. Pirates have the code, which probably states somewhere that if you mess with one of them you mess with all of them. Not to mention Davie Jones, who shepherds the dead to the land beyond; the kraken, whose hygiene is even worse than pirates'; and Calypso, who was just scary in the third "Pirates of the Caribbean." Ninjas, on the other hand, tend to work alone, but they do have the backing of the emperor (which has got to count for something), or in rarer cases, of God himself. This advantage, however, is so inconsistent that I have to give the advantage to pirates.
The good news for ninjas is that they have the superior escape arts and can always run away.