Although burn in is no longer a problem these days, I basically went on price and picture quality. I bought my 40 inch samsung lcd tv a few months back and have been 100 percent happy with all aspects of performance.
I personally own a Panasonic Viera Plasma and I have been very happy with it. My main reasoning for going with the plasma was the price, I came across a deal I could not pass up. However, one of the things that scare me with the lcd tv's is the likelihood of individual pixels going out. I have owned several lcd monitors for home computers and they have all had at least one pixel go out. I'm so anal that those individual pixels annoy me beyond belief.