Depending on what you are planning to use the setup for, I might recommend LCD over plasma.
For video playback, plasma is definitely the way to go.
However, for everyday computing, and particularly for reading text, LCD's produce sharper text, as far as I know. My understanding is that modern plasmas use some kind of image vibration to prevent burnin, which is unnoticeable while watching video content, but apparently very noticeable when trying to read small text.
LCD's are also lighter, which facilitates wall mounting, and are generally cheaper these days.