There is no one "best" martial art, as different styles have different strengths and are suited to different goals. However, some martial arts are more effective for self-defense than others. Here are some of the most effective martial arts for self-defense, according to various sources:

• Krav Maga: This is a self-defense system developed for the Israeli military that emphasizes practical techniques for real-world situations. It incorporates elements of boxing, wrestling, and martial arts, and focuses on neutralizing threats quickly and efficiently.

• Brazilian Jiu-Jitsu: This martial art emphasizes grappling and ground fighting, and is particularly effective for self-defense in close quarters. It teaches practitioners how to use leverage and technique to overcome larger opponents.

• MMA: Mixed martial arts is a combat sport that combines techniques from various martial arts, including striking, grappling, and wrestling. It is effective for self-defense because it prepares practitioners for a wide range of situations and teaches them to be adaptable.

• Judo: This martial art emphasizes throws and takedowns, and is effective for self-defense in standing situations. It also includes ground fighting techniques.

• Muay Thai/Kickboxing: These striking-based martial arts are effective for self-defense because they teach practitioners how to strike with power and precision. They also incorporate defensive techniques.

Its important to note that the effectiveness of a martial art for self-defense depends on many factors, including the practitioners skill level, physical abilities, and the specific situation they find themselves in. Ultimately, the best martial art for self-defense is one that the practitioner enjoys and is willing to practice consistently.