What martial art should you take up?

The martial art you take up all depends on what you want to get out of it , if you want a martial art that offers you a fun sport as well as combat training id recomend taekwondo, kick boxing or judo , if you want a martial art that emphisizes on self defence go for silat ( full of different strikes , chokes and deadly attacks) or wing chun ( a style of kung fu that emphisizes hundreds of counter attacks and deadly punches and open hand attacks ) if you want a style that is a little different i would go for ninjutsu ( will teach you how to sneak around , conceal your self and spie on people as well as how to fight) or Tai chi ( it may seem not very deadly but it will teach you how to be relaxed , how to control an opponent and your own body as well as how to fight!)

Of course its important to try different things and see what you like , and remember that having fun is an important part of it!)
Try a few and pick one, I tend to suggest jujitsu but at the end of the day it depends on what your looking for. Most martial arts clubs give you the first lesson or two free so take advantage of this.