[Deer]

Krav Maga is actually really effective in close combat situations. It is about using the quickest and most painful strikes in order to deal with an aggressor. That's pretty essential in a real life scenario.

Also, don't get too hung up on what martial arts you do. The chances of you getting into a fight with another martial artist is highly unlikely so just do one that is enjoyable to you and has a good instructor.

There are some bogus martial arts out there though so definitely give the unusual sounding ones a good research.

As percy says, Boxing, Kickboxing, Muay Thai, BJJ, Wrestling are probably the most tried and rested and will put you goodstead. Karate, Judo are effective but I'd say much more limited than the others.
The rest like Aikido, I'd keep away from.