What's the best martial arts to study for self-defense?

As a few others above mentioned, your list doesn't have the styles native to the Phillippines and Indonesian islands. Kali, Arnis, Escrima, and Silat are all top-notch self-defense systems. I'm a former amateur boxer - and I would still steer you towards these styles. Boxing is very effective and will arguably get you in better shape, but it's certainly not as complete. The styles of the Phillippines are street-fighting, survival techniques with rigorous and practical training. This is a great info page on martial arts of the Phillippines: http://www.maelstromcore.com/history/index.html

Find the closest Chinese Kung Fu academy. I recommend Buk Sing Choy Li Fut

For me it is Dekiti Tirsia Siradas. Its a complete martial arts with weapons, empty hand and ground fighting.

Well there are some restraints you need to think about when choosing what martial art to study. Maybe the following article will help you reach a desicion, http://www.markstraining.com/2008/03/which-martial-art-is-best-to-learn.html

Given those choices, I would pick karate. Boxing and Kick-Boxing are great fighting sports, but they don't teach you much in terms of escaping a situation: You'll have to stand there toe to toe. That's good for fighting, but you said self-defense. And there's a world of difference between the two. Karate is just more versatile.

It all depends on whether you want to learn how to fight, or if you want to learn how to be able to defend yourself. Most people get involved in martial-arts because they want to learn how to fight, and not on what martial-arts is all about. If you just want to be able to defend yourself, study Judo. The premise of the discipline of Judo focuses on self-defense. The origin of Judo was just to be able to defend yourself and not using offense to hurt someone. That's why you see a lot of submission moves in Judo. If you just want to be able to fight, study something like Jeet-Kun-Do. Learn the origins of these arts. Read up on them. You will find out things like nunchakus, or numchucks were originally used to mash beans. Generations ago, in the Far East, many farming or gardening tools were used as weapons to defend against the sword, or the bow,etc. You will also learn things like the definition of Karate is "with an open hand." Jeet-Kun-Do means, "the way of the intercepting fist." Just don't take Akido because you saw, and liked, Steven Segal movies. The art form of Akido doesn't use and kicks or punches, but you would never know that that's what Segal Studied.

If you're in the philipines then you can study silate and kali! I would say kick-boxing is good because it is hard and brutal. Next would be karate. Boxing is good too, but it is also good to be able to kick. If I had more time I would do a combination of kicking and punching styles.

There are some pretty awesome native phillipine styles. But out of that list you gave, i'd say boxing. Boxing is the most immediately street effective out of what you gave, and by immediately street effective I mean, karate for instance, takes a long while to learn properly for it to work against an unorthadox fighter. but boxing you can use almost as soon as you start, and I beleive is better than kickboxing, because on the street your gonna want both your feet on the ground to avoid falling over adn ending up rolling around on potentialy dangerous floors with an opponant that is potentially holding a concealed weapon.

Muay Thai Kick Boxing bc it teaches you the art of eight limbs (Fists,Knees,Elbows,and your Legs) it simply turns you into a weapon