So what is your favorite style? Or is it your favorite style of kicks? Or is it just your impression of the martial arts of why is there so many variations of kicks if they all do the same thing?
Chinese Martial Arts focus on soft kicks but yet use internal force to exert physical force. Japanese Martial Arts are focused in force and power to execute just one kick to blow a powerful attack. Korean Martial Arts use multiple of kicks yet for quick and speed to generate power. Other styles pick up from other styles to either imitate or copy the same kicks for mere of street self defense. While such styles as Capoeira is more of a dancing Martial Art but yet to manipulate acrobatic move of kicks.
Why so many if they are basically the same? Its really about preference. Each style is specified to use the kick for that specific moment. Styles such as Muy Thai focus on damaging the bones of the opponent until the attacker can no longer withstand such power. While Tae Kwon Do is about high and speed kicks from a long range distance, that will knock out an attacker in a short few 3 to 5 kicks, and manipulate the eye of the attacker to confuse the opponent.
Japanese Karate is used after the attack of the hands to blast the attacker after the punches are struck at the enemy. Each style has their interpretation for the reason of that kick to be used in a self defense or in a fight. Not all styles will focus on the kicks or the range of the height or to the body, but yet each system has their views how to throw the kick. How it is taught and used all depends on the interpretation of that kick to be used in an attack against the opponent.
What style is the best style to used in kicks? There is no perfect style, only how perfect it is used by the practitioner to make it work for them. Some like power kicks to generate speed. While yet speed is generated to generate power. While internal strength in the kicks can generate the speed into the power of that kick. It all depends what you are taught on about each kick.
You wish to learn what are the best kicks, you have to practice the style and learn about the system, and understand what you can develop in your training sessions in that art. No style is the right or wrong answer. It's how you apply it to be used in your own training sessions. It is all depend how you are taught how to kick for that specific move and how to time and strike with those kicks.