ok who would actually care and i have never thought about this question before in my entire life. no offense but this is the stupidest thread i have ever seen. although it is kinda fun to read the comments. =)
it took pretty much forever for me to decide, but I've decided on ninjas and here's why (Please understand that I am a girl =D):
In actual history, Pirates were bloodthirsty, raping, robbing, plundering, killing fiends. Ninjas were warriors, fighters for honor, and not necessarily evil.
Pirates are not hot. I mean, how many sexy pirates are there? There's like two and a half. Jack Sparrow (In all honesty, I don't think he's hot. Sorry.) Will Turner, and the half is the Dread Pirate Roberts aka Westley. (He's only half 'cause he's not really a pirate.)
What about Ninjas? Most ninjas are hot.
So, that's my deciding factor. Pirates are cool, but only in the entirely fictional sense. Ninjas are cool, in reality, and fiction, and they're hot.