Two of the most common questions I get about martial arts schools are:
"What style do you think I should do?"
"What do you think about X style?/Is X style good?" (Where X = Krav Maga, Aikido, BJJ, or whatever).
People seeking martial arts training often focus on the style first. There's an assumption that if you just find the right style, everything will fall into place. It's an understandable assumption, but it's a really poor way to approach things. Once you've figured out your goals and decided what you're willing to commit to, the next step should be seeking a coach, not a style.
First, while styles can be a vaguely useful short hand, they rarely capture the entirety of what's taught in a particular martial arts school. The more widespread and popular a style becomes, the more this is true.
For example: I used to study Uechi-Ryu Karate a number of years ago, and the variations in people's practices of that particular style were astounding. There were schools that focused exclusively on rote practice of kata and prearranged drills, while there were others that added BJJ, boxing, and other combat sports to their curriculum. I went to quite a few schools around the New England area over the years, and the variations in training methods was amazing.
(BTW: the broader your label gets, the less useful it is. "Uechi-Ryu Karate" tells you a little something. "Karate" is a label so broad as to be completely useless.)
Second--unless you specifically want to study a particular style as part of your goals (more on that in a minute), chasing after a particular style may cause you to miss valuable training options elsewhere.
For example: I get a lot of questions about Krav Maga from people who find out that I teach self-defense. And here's the thing about it...there are some great Krav teachers out there. There are also some awful ones whose only value for self-defense will be stealing all of your money before the muggers do. While traditional arts (or sport arts) sometimes have a rap as being poor self-defense training, some traditional instructors make a point of staying very up to date on modern self-defense concepts and methods.
Just looking at the label won't tell you anything about how a particular school is run. You might find a school that teaches the greatest style in the world, but if the instructor is a jerk and you hate training with him, the value of that style is nil.
Tony Blauer said some relevant to this at the Boston CrossFit Defense course: if you train with a sincere, passionate, and skilled coach, you will have a great experience, regardless of what they call their style. And if you train with a shitty coach, you will have a bad experience, regardless of what they call their style.
Or, to draw a food analogy: steak is steak. It's the chef that makes it taste good. My grandmother, may her memory be a blessing, could probably have ruined Kobe beef.
So forget about style. Define your goals, and start looking for a coach who can help you reach them. (More on that in a later section).
Style as Goal
I mentioned one possible exception to this rule above: if training in a particular style IS the goal.
First, be careful with this. If you want to study, say, Hung Gar Kung Fu because you want to explore the style, do it. If you decide that you want to study Hung Gar because you believe it's the ultimate self-defense system (or worse, because someone TOLD YOU that it was the ultimate self-defense system)...back up. Is the goal Hung Gar? Or is the goal self-defense? If it's the latter, go back and start looking for coaches.
That said, if you specifically want to seek out a particular martial art because of personal interest, then you have to look for that style. Depending on what you're looking for, that may be more or less challenging. Finding a Tae Kwon Do school in the modern USA is pretty easy. Finding an authentic Japanese Koryu instructor is a lot harder.
For most people, I believe that the goal should go before the style. Know what you want, and go find someone who can help you get there.