I've taken a few forms of Tae Kwon Do, and most recently, Budokai. I've been self-training, planning to go back to it soon... very soon. The highest belt I attained, was Red... just below black, in that case. The class sorta fell apart... it was me and 2-3 other guys, and I lost interest... alas.
TV is NOT a good martial arts instructor... it may teach you to look cool doing a jumping spinning outside cresent kick, but try and use that in a fight and see what happens. 99% of the time, it will get you owned. Nor will TV teach you the detailed body mechanics to actually generate POWER w/ a technique. Note, no degree of martial arts training will make you a good fighter... not necessarily. Giving the masters assistant a workout is good, but keep in mind that FIGHTING makes one a good fighter... not sparring. I've come across a number of black belt "masters" who aren't worth beans. Not that I'm hot spit... I'm just saying, there are two types of martial artists... those who like the "art", and those who like the "martial". Don't get too cocky... there's no substitute for REAL experience, and all masters are NOT created equal. If you're giving the masters assistant a run for his money at blue belt, you might consider finding a new master. I may not be a master myself, but I've had enough experience to spot a false master when I see one... I had to check out four different schools before I found one that was worth it... I have a lot of free uniforms.
It amazes me... what passes for a "master" sometimes. One school I looked at... the black belts couldn't even throw a solid snap kick! Bah!
Note, if you practice martial arts consistently for a few years, you'll surely be in shape. If you practice firing a gun consistently for a few years, you'll still be a lard-arse. Martial arts, while not all that valuable on the modern battlefield, can be extreamly valuable to anyone not in a life/death situation on a daily basis. I love guns, but martial arts is generally more valuable... it teaches you respect, keeps you fit, and trains you to AVOID incidents that would require someone drawing a gun, thus lowering your chances of going to prison over some stupid bar fight.