For those of you who are not interested in ring competition or MMA fighting I recommend the Muay Thai Academy International (MTAI) in Santa Clara, CA. MTAI, the oldest muay thai school in the US offers old style, military and street combat training based on ledrit, muay baron, muay chao churd and Burmese Bando styles. The school rarely advertises and provides a hard core training regiment that focuses the student on efficeincy of movement, building power and preparing the student for fighting multiple opponents. The school specializes in close quarter combat, and I mean close.
In the MMA, commercialized 'Fairtex' world of retail martial arts MTAI gets little respect, due mainly to the fact that the school refuses to compete. But it must be remembered that many of Muay Thai Academy students are law enforcement officers, military special ops, executive protection professionals (not bouncers), and federal officers. Sport muay thai and MMA does not work in a counterterrorist situation.
Another thing to note is that MTAI spawned many of the most repected names in the MMA world. Javier Mendez, founder of the American Kickboxin Academy in San Jose, home to many UFC fighters got his start as a student at MTAI, along with the late Alex Gong of Fairtex fame and the founder of Rey's Muay Thai/Wing Chung in San Jose.
Here's a link to the site: http://militarymuaythai.com/
Its a bare bones site, but what they train is lethal and more effective than anything else out there (includine krav maga). Its worth a look.