I also voted Ninjas, but this was a hot debate in the pub last night, so summerise the arguments for each side:
*Pirates
-Their are famous pirates - Long John silver, Blackbeard, Captin Pugwash, each one is well known as being extreimely cool
-a life of desert islands and gally ships with now laws and cannons
-the parrots, they are pretty cool arn't they?
-the one liners like "shiver me timbers" and "arrr me matey" we liked them
-invading other ships and islands
*Ninjas
-they are very stealthy
-they get the girls
-that all-black outfit is pretty cool in its own way
-the training and dedication is way impressive
-way cool fighting & weapons