What is a good fighting style to learn?

It really comes down to the instructor, not the school. There are good and bad schools in all styles, so you have to be careful. Avoid McDojos: long term contracts and the promise to make you a black belt in a given time. Talk to current students. Look for a mix of ranks including various black belt levels. Attaining your first degree black should not be the end goal of a training program. First black really only means that you are a serious student, in traditional circles.