Karate Sux... If u want anything worthy at real fights try Ed' Parkers kempo, Jeet Kune Do, Brazilian Jiu Jit Su or Shin Tzu...
More known Martial arts useable in streets are taekwondo, jiujitsu,thai boxing, kickboxing n kung fu, but karate & Judo sux ass (I even know a black belt 1st dan in karate who thinks the same as me)
Anyways, what can teach u the most in free fighting is... Fighting!!! Get used to other people's patterns of fighting, get used to hit and be hitted... that's the best way...