I cant believe anybody has given any answer other than KRAV MAGA! That art was literally designed for exactly what the OP is looking for: street fighting defense.
You do understand that Krav Maga is a MILITARY COMBATIVE. Originally taught only to the Israeli military forces. Its not designed to temporarily immobilize, or temporarily hinder an opponent so that the user can run away. Its designed to KILL, just like with every other combative ever developed. Perhaps you should watch something other than Human Weapon before determing which Art would be best
Sig courtesy of that photo-matic magician limba
I went out the way that I fight. I went out on my shield. Thatís it. Done. --Chuck Liddell
My goal is to end my opponent --Carlos Condit