I think anything other than Brazilian Jiu Jitsu, boxing and kickboxing are completly unrealistic and wouldnt be practical in any fight situation.
There is a lot of truth in that but not totally. From the street fights I have been in and seen, most all of the detailed wrist locks(I had done some Combat Hapkido) and overly fancy crap go right out the door. However, I wouldn't say that
anything other than those are completely unrealistic and impractical. Some are pretty amusing when it comes to reality though, but those are usually for the more discipline and art aspects.
For the OP, I have been doing Commando Krav Maga(as opposed to traditional Krav Maga) for some time now. It's technically not a martial art, it's a fighting system. It is a constantly evolving system that does not claim to be a "end all" "wonder" system, but simply to increase your chances to survive the best you can in any kind of self defense situation, and it does that very well. We frequently do work outs to begin the class and end with "pressure tests" where multiple attackers(with whatever; guns, knives, punches, chokes, ground, etc...) really come after you for an extended period of time in different environments with situation challenges(for example, outside in a gravel parking lot at night, maybe you have to spin until dizzy and our instructor does not care if it is raining, ha). It is intense and sounds overwhelming at first, but if you're serious and dedicated to self defense, you progress right into the thick of it before you know it.
Like tom said, I love the level of focus I get when in class. Also, that state of "no think, just do!" It is not common for me but great when it happens. I don't know why, but sometimes after a tough but successful class, with the feeling of accomplishment comes this extra energy as well as a want to socialize. When I am in this mode I become a great speaker(otherwise I am terrible) and excel at communicating. It is very strange and rare but I really like it when it happens.
So that feeling afterwards, along with confidence and the knowledge/ability of self defense is why I participate.