When I was looking at TV's, after doing a lot of research, I decided DLP was the way to go for me. In my opinion, the only real benefit LCD has over DLP is the flat screen. Their picture qualities are about the same. But I've seen some great looking DLP's that were only about a foot deep. However, DLP has a drawback in that the bulb will eventually wear out and need to be replaced. But depending on how much TV you watch, this could take 10 years.
So to me, if you absolutely MUST have a flat screen TV to mount on the wall, go with an LCD. But in my opinion, DLP is a better way to go. Their picture quality is great, and they're cheaper than LCD's.