Any full contact combat/sport training helps. It doesn't make you superman but even "just" doing wrestling puts you way ahead of most people you'll meet. Mix it with some pure self defense technique like finger manipulation, eye gouges and ear twists/tears, and you should be able to handle most *unarmed* 1v1 situations.
Also, don't forget that running is a great self defense you can't get sued for.
Also, don't forget that running is a great self defense you can't get sued for.