Which martial arts is the best for self defence?

It is really hard to say .There is a saying that the best self defence is attack.so I Bruce Lee is the martial art.His attact speed is so fast that no one when he began to to attact and how.

I would think they are all good for self defence. I can only give you my opinion on my one, which is Krav Maga. Krav is good for self defence because that is what is was designed to do. Every class as well as learning the techniques, we are taught to always be aware of a potential attack and often we do 2-3 attackers to one defender to practice this. Krav is also very easy and quick to learn, so that even after one class you have learnt to defend yourself a bit.

There is no "best" martial art in my opinion. We martial artists learn from other martial arts to expand our knowledge and gain new techniques and respect i guess, but if i would name one, i would say Aikido has some beautiful techniques for self defense, i use some techniques from Aikido to use in my Tae kwon Do.

I have trained in Karate,Taekwondo and Taichi.For practical knowledge and street self defence I train in the Modern Street Combat System knowledge of which can be obtained from Dave Turton.