what is the best self defense...is it through martial arts or through weapon....

I guess, Martial arts? It is more safer than weapons. sometimes the weapon may cause damage to ourselves, so its a bit risky. Also with one weapon, its a bit difficult to handle too many people. You can stab only one at a time, where as in martial arts, you use your both hands and legs, so its more protective i suppose. And as you said, for killing it needs weapons. But who wants to land up in jail?:p So better make them suffer with wounds and fractures, just giving them a rememberance that we are terrors and have no fears..lol

well if you are talking about self defense then ofcourse its martial arts. Because you can get attacked when you are in bathroom taking a bath without any weapon. Weapons could be used for offense and in very rare cases it can be used as defense.