KF San Soo, Brazilian Jiu Jitsu, Thai Boxing, Standard boxing, and any base martial art (ie Tae Kwon Do, Judo, Tang Soo Do,etc.) Nowadays, a good practical fighter has knowledge in a lot of different arts, and knows how to apply them in a situation. That is why the original UFC was classified as a "mixed martial arts" tournament. You can't win a street fight or a MMA tournament simply by knowing how to punch and kick only, or knowing only 1 style. With the new UFC rules though, it's anyone's game now. But back in the starting days when they had no rounds or time limits, BJJ and Royce Gracie always came out on top (or on bottom, but still won). The original UFC was a lot more true-to-life than it is now. Granted, many pure street fighters have no knowledge of martial arts or grappling, but YOU need to be prepared for any eventuality. Do you get a resume from the guy who's about to pound you? You never know who you're dealing with. I'd say start off with a decent stand up fightning skill and also get well versed in ground fighting in case you get dumped. If your opponent wrestled in high school, then you're at a distinct disadvantage.