I've been studying Muay Thai for almost 3 years now in addition to Kali Escrima, and BJJ.
Muay Thai is a brutal form of martial art. One of the very few that implement elbow and knee strikes in close range. The thing about it is even though form is important, endurance and power is what makes it so deadly. It is also an offensive art were more of the common forms like Judo, TKD, and Karate tend to only offer an offensive move in response to an attack.
Muay Thai is not pretty to watch, there are none of the spinning back kicks and all that crap. It is in your face, beat the other guy into the ground, fighting.
That's why I love it:aok