Yes they have guns. But when a ninja is stealthy then what's the pirate going to aim at? The ninja will come up out of the shadows and assassinate the pirate.
Oh then who's cooler. . . I'll still say ninja because of how they dress in all black, some with mask. My favorite ninja's would have to be Scorpion and Sub-Zero.
Pirates are too sloppy. Never liked them. Except for Jack Sparrow.
There have been many Ninja vs. Pirate threads on AG. I remember FT's Ninja vs. Pirate vs. Samurai thread.
Let's answer these questions seriously. I remember FT's old thread; Pixie would go on and on about how pirates were superior. By now, I've been won over. Ninjas were assassins, contract killers, spies, agents, mercenaries, whatever. That doesn't sound exciting to me. Samurai and bushido doesn't appeal to me, though I have to admit the equipment the samurai possessed was very kick***.
Therefore, I'd like to be a pirate. Just remove all the stereotypes. A pirate can be many things - hell they're even pirates out there today. (Honestly, I wouldn't want to be a modern day pirate)
I could try and survive the dangers of a life of piracy. Think of the Golden Age of Piracy and the Spanish Main. Sure, pirates have been romanticized, but real life pirates still had a chance at becoming fabulously wealthy.
If I wanted to be in Feudal Japan, I'd choose to be a shogun. Also, if you factor in all the rubbish urban legends, folklore, mythology, pop culture and tall tales provide I'd still be a pirate. The only difference is that I'd have a hook for an arm, a peg for a leg and I'd be even more wealthier.
Ninjas are still cool though. (Yes, I'm voting for piracy.)