I would suggest Karate as it is obviously based on self defense but the karate I do (Wada Ryu) incorporates loads of different martial arts whether it be judo, capoeira, boxing etc etc. Also it's good if you want to do a varity of fighting including points fighting, sparring and grappling. In response to whoever said it's kid orientated that can be so in some cases but if you have a good enough trainer he will train you in a way that will be of value to you sure to start with it's the boring block kich punch but as soon as you get into it it you will soon be throwing people and locking into their every limb.