I would definitely take off gars and pbass off the list. They are only preditory. Isn't this the same w/ African tigerfish?
It is hard to say what is most aggressive when I don't have experience w/ a lot of fish on the list. My experience w/ cichlids is that they are usually only aggressive w/ other cichlids as that would be thier main cometion.
African cichlids are supposed to be very aggressive and I am surprised no one has mentioned them.
I've seen videos of dorados and common wolfs and they would get my votes.
Another I'd like to add are c
Chinese algae eaters. They can be really nasty when full grown and males will ram other fish w/ their horns and suck on the sides of other fish.