They all have their different pros and cons, I personally went with LCD because there were no 32" plasmas and I didn't think the premium for an LED TV was worth it.
There is little difference between an LED and LCD TV, LED TV's use a different type of backlighting which allows the TV to be a lot thinner, more energy efficient and they generally produce deeper blacks. Plasmas are very different. They're usually only available in 42" and upwards, they are very heavy, they consume a lot of power and they're generally less reliable. But in exchange for this, they usually have a faster response time, better picture quality and deeper blacks than both LED and LCD TV's. Plasmas aren't as bright as LED and LCD TV's and have a reflective glass screen, so having a plasma in a well lit room isn't a good idea, plasmas are far better in darker rooms though as they have the deepest black level, while an LCD TV may appear washed out.
Basically, it all depends on what you're looking for and how much. LCD TV's are the best for general use and for smaller screens, plasmas are the best for home cinemas, and LED's are great all around, but you'll have to pay a premium.
