take the style that you like and suits you. Pretty much any style will work if you train it correctly.
Dont knock TKD, its a highly effective martial art with military roots. But yeah, there is an impression its all flying kicks and tricking. Which is part of it, if you can do that then you can snap a kick out cold to head height at any time, or more likley knee height at max. You dont actually fight like that! Its also a very effective "self defense" art, so long as you dont get taught by a sport focused club. Although if you want fitness, then sport focused TKD and MMA is brilliant if you are not to concerned about practical applications.