For someone wanting to learn self defense over sport, and as far a "styles" go, most Krav Maga stuff looks pretty good. I say that without having studied KM. You're just more likely to find a school around the country.
My background is in TKD, Arnise (a lot of knife self defense), Jeet Kune Do, some Aiki-jutsu and Jujitsu. What's most important is who you are training from, what's their background, and their expertise. With the exception of TKD all my training was under a former police officer and others in the organization. The advantage of that was in getting taught by people having first hand experience....which isn't the same as getting instruction from a TKD instructor who may have never been in a street encounter in his life.
You will fight the way you practice. So if you take a Judo class you will learn some good take down tactics (Judo is a good sport for kids and useful on playground fight) but you will not learn how to jab your finger into an attacker's eyes. So if and when you get into a street encounter your training, or lack thereof, will kick in (no pun intended) you'll resort to that training. You might instinctively go for an arm bar when a strike to the attacker's eyes would've quicker and easier. It won't look good on a movie set, though.
Brazilian Jujutsu (BJJ) is very useful to learn. It maybe the best system for learning how to fight/wrestle on the ground. But the sport side of BJJ teaches to deliberately take the fight to the ground. That's not something you want to deliberately do on the street. What if he's got a knife or a friend of his near by has one? You can't run away. TKD doesn't even teach you to wrestle or go to the ground.
These are some videos from my main instructor
https://www.youtube.com/results?q=ho...=w1&authuser=0. We incorporated a lot of drills from Arnise to build flow but we also would mix it up to introduce an element of chaos.
https://www.youtube.com/watch?v=FzgdOzJASeM
If you want to learn Close Quarter Combat (CQC), and not just a martial sport, you got to shop around and interview the instructor. If he's a former navy seal or army ranger with a good martial arts background you're probably good to go. In an instructor, I want an emphasis on breaking apart situations/scenarios and then using strategy and tactics to deal with that situation. What are the what/ifs? What improvised weapons are in the environment? Incorporate training guns and knives, and multiple attackers. A seasoned police officer who's had to mix it up a lot is a good resource.