One day I decided that I didn't want to just exercise anymore. After years of just weight lifting and running I wanted to do more. I turned to martial arts because it was one of the few sports I had excelled in as a youth. I found Modern Combatives through the yellow pages, gave 'em a ring, and later that day I found myself taking a private intro class. A couple days later I took my first full classes and I came back beat up, bruised, exhausted, and completely hooked!
Going in I knew little about the different styles of fighting and training and I now consider myself to very lucky for having stumbled across Modern Combatives. They don't beleive in tradition and titles. They believe in training with "aliveness" meaning you don't just punch/kick the air and bags all day. My first day I was dishing it out and getting wailed on. They teach a complete game of stand up (boxing and kickboxing), clinch (close quarters control), and ground (Brazilian Jiu-Jitsu) that's about as close to "no rules" fighting as you're going to get.
The coaches are incredible and the environment is great for all ages, genders, and skill levels. More info on the Modern Combatives website.