For self-defense, using the modern definitions of each style, I would choose Judo. In most cases Judo will allow you to remain on your feet. This is valuable because you can get away from the conflict before it escalates and someone gets seriously injured or killed. There is absolutely nothing to gain from a street fight, but you can lose plenty, even if you "win". The best choice would be not to participate at all. But, if you are attacked, I believe it is best to strike, get the guy off you, so that you can get away. You cannot run or even walk away while laying on your back in the guard. Maybe you can break a guy's arm, but he might have 5 friends already arming themselves to attack you while you are locked up on the ground. Judo will allow you to hold you balance, deflect an attack, and get out of there before the worst situation ever happens. This is the wisest move in my opinion and experience.