Im not a black belt but I can tell you the most effective traditional weapons to master would be the bo and the escrima sticks. Its theory is simple there are many long two handed things you can use like a bo and if you master escrima then you can use two short handed weapons that you might pick up also. Just look at condemned the videogame for 360. If that person was a master of bo and escrima he could move the weapon faster and more effectivly not just swing it. It would make it so much easier.

Learn bo for two handed weapons and escrima for short double handed weapons and you can control everything better.

I think the best weapon for true self defense is...

The empty hand.

There are a few reasons for this.

1. If you defend yourself against someone and the police come, you won't get hauled in for aggravated assault/assault with a deadly weapon, ect...

2. Most times, there are no weapons around, or even something you can use as a weapon. There won't be a mop in a parking lot. There won't be sticks thick enough to use as weapons in just lying on a street corner.

3. No matter where you are, who you're with, or time of day, you always have your hands and feet. Those never leave you. You have more control over those than anyone will ever have over a weapon. They are not an extension of you, they ARE you.

Anyway, that's my 2 cents

Escrima should cover everything, long/medium/short stick, dagger/knife and empty hand.