If you're looking to kill somebody, there's nothing better than ninjitsu

Like I said earlier, ALL styles have their own pros and cons.
So, whether there is a "best" or "worst" style is very debatable.
You can also "kill" with what is not strictly speaking a martial art, namely close combat, as taught in the army.

Just to clarify my previous post, I respect all martial arts, My son is currently taking Karate and has 3 yellow stripes toward his yellow belt, I am so proud of him. I will send a show off pic when I get them on my computer:)

Well, Archangel, I think you have every right to be proud of your son.
Whatever they achieve merits pride.
That is why I am also proud of what I have achieved thus far.
Best of luck to the boy in his further training.

Well each art is normally dependent on the persons likes, not everyone is not going to pick a art just because it seems to have a certain amount of flaws compared to another fighting style I mean most people just learn martial arts just so they can defend themselves in a every day scenario.

Anyways just adding I did Karate. ^o^ But yes all fighting styles have their own cons and pros, really its your choice in finding a way to perfect those techniques and make that flaw not so noticeable to the opposing person.

every preson have his owen professionalism, and all styles have their own pros and cons.

all kinds of Martial art have similars and differences, as to me myself, i played both karata and Tae Kwon Do.

But i prefere Tae Kwon Do becouse of its fast moves, jumpin higher, and the most importoant getting more Flexible, it makes my movement easier and faster, i even got better at sports, its not just a good excursie, but it also help you on other things in your life, such as playing sports.

Tae Kwon Do isnt easy to learn, but it is very usefull and powerful martial Art that can help you and your body get stronger and better.

You might have a point there, dre (and yes, I do notice the smiley), but that is not what martial arts are about.

Looking for some MAP wisdom here on this question:

When have you really mastered a technique?

Do you feel like you have mastered a kick when you can perform it with power and speed? Do you feel like you have mastered a kick when you can see it coming and block it? Do you feel like you have mastered a kick when you can teach it to someone else?

I am just looking for guidance as it seems in my TKD training; you have mastered a kick when you can perform it with power and speed. The aspect of blocking the kick and being able to teach it to others seems to not be very important.

By comparison, I just started taking BJJ once a week for 30 mins, and the first thing we learn is how to stop a technique, then how to perform it. I always feel like I can perform the technique, block the technique, and teach the technique after each lesson.

I think the best thing to take as a yardstick on whether or not you have mastered a certain technique is your sensei, and the examiners.
It is true, we think, if we can kick someone with speed and power, we have done a great thing, yet it does not always mean the technique has been executed correctly.
Being able to teach a technique is another thing, you might be able to correctly explain to someone how to execute a technique, but be unable yourself to do it correctly, or you might indeed be explaining it all wrong.
Blocking a punch/kick is obviously something you need, something essential, but blocking a kick does not necessarily mean you can also execute that kick (punching, kicking and blocking are three different techniques altogether).

As I said, the best guidance in this case comes from your instructor, who will be able to tell you whether or not you execute the technique correctly, or the examiner who passes or fails you (hopefully you don't have to go that far to hear the latter, and have listened to your sensei's advice before taking an exam).