I do San Soo. It is very effective, but hard to find outside California. It also depends which teacher you get, because there are two branches of San Soo: one uses a lot of very broad motions and looks more like something out of a kung-fu movie, and the second includes elements of modern styles like boxing, BJJ and Krav Maga. I've done both, and definitely prefer the second. All in all, it's a brutal and highly effective art, and probably the best art there is for fighting off multiple attackers.