I look at fighting (competitive at least) as taking place in 3 ranges (Bruce Lee used 4, but I think you get through those ranges too quickly). The ranges are striking, clinch, and ground.
You have a lot of choices with striking arts. Personally I like western boxing and Muay Thai.
Clinching is tougher to define. I put arts like Muay Thai in here as well, because it has great knee and elbow strikes, I also include Judo because of the throwing aspect, but leave out Brazilian Jiu Jitsu and Wrestling because they focus on solely taking the opponant to the ground to inflict damage.
Finally you have the ground, where Brazilian Jiu Jitsu and Wrestling are the strong points.
It really depends on what schools you have close by and the quality of the instruction.
Krag Mata
Israeli Army form of martial arts, basically a reformed style of street fighting. I studied it for a very brief period while I was in that area, hard but damn fun.
I'm looking into different types of both due to the nature of my work, and my size. I'm looking specifically for something that emphasizes take downs and self defense.
Personally, I always recommend the most "enjoyable" martial art.
Go to a few different classes, most places will give you a few free or trial classes, and go with what you find enjoyable. Most people excell in an environment that is fun.
ALL martial arts have their strengths and weeknesses. I prefer muay thai or brazilian ju jitsu.....cause i had the best time in those classes. I found karate to be too mickey mouse and children oriented...too defensive.