[Ronin4hire]

What are your goals?

If you want to become super tough and have the option of competing in the ring I'd suggest Boxing, Muay Thai or Kyokushin Karate (or any other type of full contact, sport karate). I heard Brazilian Jiu-Jitsu is pretty tough as well as Judo if you're into grappling over striking.

If you prefer to learn something traditional or spiritual then Aikido, Tai-Chi (or any other type of Kung-fu) might be for you.

Otherwise if you want to learn something Acrobatic and dynamic then Wu-shu, Capoiera or TaeKwondo might be your thing.