Actually, i see this as a perfect thread for MaximumZero (alright, everyone else too) telling us about the fights he's been in, and of course his less-esteemed clone.
This is from the first page. I'm not sure how I missed this.
Anyway, I'm gonna go read up on you guys' opinions, and possibly throw my own in the ring.
So, my own credentials: 2nd degree black belt in Ninjutsu, red band (instructor) in Muay Thai, and yellow glove (instructor) in Savate. I've taught self defense/kickboxing classes in a couple of womens' shelters, and Combatives III and IV Readiness classes to Ranger and SEAL candidates (due to the Muay Thai). Note: I'm also 5'1" (155cm) tall, and upwards of 200lbs (90kg).
In a real fight, and I've been in a few (mostly due to being a little guy with a big mouth some years back), the most quickly useful techniques have come from Muay Thai. Someone shoves you to start the fight, you grab the back of their head, and ram their face into your knee. Fight over. Kickboxing is good for stand up fighting, but I've always mixed Ninjutsu and Kickboxing to be a sort of hybrid. It's all about opportunity. Most people are not equipped to handle a lunge kick to their leading leg, groin, or stomach. Most brawlers protect their face, but not their throat or sternum/solar plexus.
My Ninjutsu training was very diverse, as was stated earlier in the thread. I learned how to fight with swords, staves, spears, the manriki-kusari, sais, an axe, a shovel, and rope. I also learned to shoot longbows and blowguns, throw knives, spikes, axes, nets, bolas, and coins. When we did unarmed training, it was almost all stand-up and stand-up grappling (which translated very well into Muay Thai.) On top of that, I did calligraphy, climbed ropes and nets, rode horses, learned to read the stars a little bit, and learned how to properly serve sake and perform a tea ceremony. If anything else, it was more like Japanese life training than straight-up martial arts.
Muay Thai, which I went into next, was very different. The classes were all business, bruises, and blood. I got knocked out several times in sparring, and had my nose broken a couple of times. We always knew when we were getting a higher-up instructor in house, because we'd wear headgear those days to spar. You had to be strong and fast, but mostly opportunistic and vicious, or you weren't going to make it. We neglected everything outside of sparring, toughness training, and endurance training to the point that I was shocked to see Muay Thai fighters doing a spiritual kind-of-dance before fights in my first tournament. Due to my atheism, I was never allowed to join them (I was always just held off to the side of the ring while another fighter or a referee took my place), and I was never even shown how to perform the dance. Honestly, I kind of feel like I missed out on a whole facet of Muay Thai because of that.
Training in Savate was weird. This is the only time I've ever worn shoes onto a dojo floor, and it felt awkward at first. Classes were very fast and loose, but always challenging. In a way, Savate was less about proper technique and more about creating an opening in the opponent's defense and exploiting it. We learned things that were very awkward, and somewhat counterintuitive, like using a lunge kick with your heel, instead of the ball or whole bottom of the foot. Misdirection was a huge part of the game, as Savate was initially a form of street fighting. Feints, spinning kicks, sweeps, and leg kicks were very common. Landing spinning kicks was very uncommon, as they were mostly used to set up other techniques. Grappling was against the rules, which was very disappointing.
Anyway, the point of this is to go with what you're comfortable with, and what works. Rule one of combat, however, for any style is: If you can avoid a fight in any way, do so. If you can't, put the opponent down and get the hell out of Dodge.