Comment on What martial arts are best for developing confidence in a fight? by rebel_squall_leonhart.
My experience is in the following and i feel they are as such:
Japanese Jujutsu: instills a lot of confidence (rightly so) and mentally prepares you for the decisions you will need to make and the dangers you will be facing. Generally teachers of this art try to be down-to-earth and serious about fighting due to where it came from (samurai learning to fight without a weapon against people who had armor and weapons).
Bujinkan Ninjutsu: Lots of confidence but you really have to consciously look for ways to disable opponents without maiming them. It tends to be taught with a pattern of break this bone, then this one, then kill them. Or kill them, kill them again, and kill them again. You have to decide if this is something you would want. (American dojos of the Bujinkan can also be somewhat… dramatic)
Aikido: Less capable and less confidence. But you don’t have to worry about hurting anyone. I was never taught any way to actually injure a person… but that does mean that you’re more open to injury yourself.
Tae kwon do: not much experience. Good striking (especially kicking) wouldn’t recommend it as a stand-alone art.