Which Is The Best Martial Art For Self Defense?

I would say that all of the martial arts are good for self defense, some require more practice than others and some are more practically applicable in the short term that others.

Judo for instance has no offensive hand strikes or kicks, which may not be great in a fist fight, but may be great if someone gets you in a head lock.  Taekwondo may be good if you want to kick someone in the head, but it will take significant time to master the technique, develop the power and the flexibility.

Most cities have classes in basic self defense taught by police officers or ex-army instructors or people who specialize in self defense for women or defense against knife attack etc.

Remember that the best martial art is the one that suits you and I've always found the most effective self defense class was the one I learned early on, learn to run, and run fast, 9 times out of 10, it's the most effective technique.