Krav Maga
The art of the Israeli military. Or so the branding goes. There are probably some similarities in training, but from what I saw on Fight Quest years ago it's debatable what the carry over is between military and civilian. I've gone to two different Krav Maga schools, which I guess are slightly different because there's some schism between affiliations. There were some differences in training, but not a huge difference. If you put the curriculum side-by-side, I'd say there is a 60% chance I could tell the difference.
One of the good things about KM is that both places I went to had a clear curriculum, the IKMF affiliated school in particular. They also pushed aggression. This is kind of a mixed bag - for self defense, being able to go from 0 to 100 quickly is a great skill to learn. On the other hand, I think some of the training teaches bad habits. They would do a multi-person drill where you would strike a target 2-3 times, then engage a new target. Continuing to engage a group of people in hand-to-hand combat is a sure way to get hurt or killed. Or you might break a choke hold and do 2-3 strikes in the air. You're training yourself to throw punches when you're actually too far away to hit someone or not targeting them.
However, they also did actually teach verbal deescalation as a first step (though only as a precursor to attacking someone). I think better training would be that the potential assailant either randomly disengages or attacks following attempts at verbal deescalation, so you have to learn to read if aggression is appropriate or not.
I didn't like some of the techniques and didn't like the way some were taught. The example off of the top of my head was wanting people to keep their hands up when kicking. In every other martial art, for example, you either post your hand on the opponent or swing your arm when throwing a roundhouse kick. Not in Krav Maga, though, you have to keep your hands up the whole time! From what I've seen online, some KM instructors have been breaking off and improving on the curriculum - deleting bad techniques and training.
I think they also overstate the value of illegal techniques from sport combat. Kicking someone in the nuts is fine. It might work, but you definitely shouldn't assume it's going to end an attack.
I think KM is a fairly decent self-defense overall, though, for short term training. I think it will give people some useful tools and probably make them more confident and aware of their surroundings (which in itself probably makes you less likely to be attacked). I think for longer term training, it probably isn't as useful. It starts morphing towards some sort of weird kickboxing/MMA thing with worse technique. There really isn't any combat sport value.