You could take any style, and if you don’t have good instruction or train right, for self defense it is pretty much worthless. One on one in a controlled envirment, or even your average street fight, BJJ in the hands of someone well trained would be hard to beat. Put that same person against 2 or 3 attackers, or against somebody that knows how to use a knife, and it would be adifferent story. I am not saying that most strikers would fair any better in these situations, but if they trained for them they would have more options then a strictly ground fighter.

There are so many styles for a reason. There are different body types, different temperments, different goals. Far more important then style is what fits you, how well you are taught, and how you train it.