Have taken a derivation of Ed Parker's American Kenpo for the past eleven years. I'm a fifth degree black belt, although that doesn't really mean much unless you're at my school and can verify that they don't just hand those out in exchange for cash. There are two of us fifth degrees, and we're the top students at the schools under the teachers.
(Note: I'm not saying this out of ego, but to pre-emptively defend the school. I've advanced very quickly for my school -- far more quickly than just about anyone else except the teachers. In high school and college, I didn't have a ton of hobbies. All I pretty much did was Kenpo -- and I have an excellent memory and a history of athletics. So eleven years = fifth degree black belt is not a normal yardstick or timeline for my school. We are not "a black belt school" or anything, and we currently have only two students above first degree black belt -- me and my buddy, the other fifth-degree.)
There are a ton of different martial art styles, and a ton of different reasons for taking martial arts. Your art being represented in the UFC has little to do with whether it's valid, or whether it's not valid. Having done some Jujitsu on the side, I can say that it helped my Kenpo a lot, giving me a few options I didn't have from pure Kenpo training. The UFC is a sport, and it's possibly as close as you can get to a no-rules fight, but it's still a sport. You can't go for the groin and you can't go for the eyes, and you're fighting on ground that allows softer falls, and it's considered ungentlemanly to break people's limbs, which is all kind of limiting -- both for the Gracies and for other people. In the "real fight" situation, it's gonna go something like:
Boxer-type runs toward Grappler
Grappler tries to take down Boxer
1) Boxer gets in a punch, stops Grappler from shooting in, and then hits him a bunch more times, and continues to hit him until the Grappler is out
2) Boxer gets taken down, lands on pavement, gets a minor concussion, and then has all of his limbs broken systematically or is just choked out.
I'm not saying that the Gracies would lose if groin shots and eye gouges were allowed. I'm sure their style has defenses against that sort of thing. But using the UFC to determine the best martial art is silly.
Kenpo has gotten me in really good shape since I started taking it back in high school. It's also given me much better confidence (ah, geek pariah life), helped me be at peace with myself and all that other good enlightenment stuff, and gotten me out of fights. Since starting Kenpo, I've never been in a fight -- and I owe a lot of that to my training. Being able to stare at someone with the confidence of knowing you could spray them across the wall if necessary, and then telling them that this is silly and that there's no need to fight about it, is a whole lot more of what martial arts is about than going into a stupid fight you could have avoided, coming out with bruised knuckles, and thinking you're a badass. (YMMV, of course)
By the way, I know about most of the styles I've seen mentioned here, but not all. How about doing this with a format?
My style:
FOCUS: KICK/PUNCH VERSUS GRAPPLING
Mostly kick-punch at lower levels. At upper levels there are more takedowns, chokes, and traps (although we usually just break the limb instead of going for come-alongs)
RANGE: LONG VERSUS SHORT
Short for most of the time. We're more into elbows than really long-range kicks. Maybe medium, since we do a fair amount of punching and kicking, but we rarely have strikes that would push the person back away from us -- that just stops us from continuing to hit him.
STYLE: PRAGMATIC VERSUS ARTISTIC VERSUS SPORT
Possibly this one is a loaded term. I think that Kenpo is a nice-looking art when performed correctly. But the fact is, we're way pragmatic. We don't kick above the waist except in katas (sets, forms, dances, whatever you call 'em), and given equal opportunity, we're more likely to gouge someone's eyes than kick him in the head. We hit the groin,
(Please note: I'm trying not to load this one. I consider TKD to be very graceful and athletic and extremely cool-looking, for example, but the jumping kick was designed to work against opponents on horseback, and there aren't a ton of muggers on horseback these days. And it varies from school to school -- some TKD schools can be very pragmatic, but most are more into having a good workout and doing cool acrobatic stuff that is more into art and less into practical application, or into getting set for the next tournament -- none of which are bad things.)
Oh, and one last thing: What bugs me worse than anything else about some martial artists is the idea of how Master X studied Karate, Aikido, Jujitsu, Savate, and Kung Fu, and created a new martial art that uses the strengths of all the styles -- and Master X is 30. I completely agree with everyone who talks about one year of martial arts being good to get you into trouble. And practicing ten martial arts for 1-2 years each is like trying to string the first two chapters of ten different novels together to get a complete story. The best thing that anyone can do is study one martial art consistently and then augment it with a complementary style on the side. Do ten years of karate and three years of aikido, or ten years of jujitsu and three years of escrima. Think of it like multiclassing.
-Tacky