They both are so similiar. Both love to fight, both love to eat a shit load, and if they set their mind on doing something, they won't stop until they have achieved that goal. If they get beaten, they come back 10x stronger and then kick the bad guys ass. But I think I'd have to throw Luffy in front only because he knows when someone needs to die. Unlike Goku who gives everyone he meets a chance to live. Luffy just kills them. I know if Goku did that, then Piccolo wouldn't have ever been in DBZ, but I'd say it's worth it.