I would have to agree that today plasma is not necessarily worth the extra money. One reason is that if a pixel goes bad on a plasma screen, you get a vertical line AND a horizontal line all the way across the screen at that point, essentially ruining the picture...and the only way to fix it is to replace the display (i.e., almost the full price of the plasma TV originally!). Ask me how I know!
As a result, if you DO get a plasma screen, be SURE you get a 5-year extended warranty (which should cover the above)! With other types of displays, the extended warranty is arguably less important (for example, if a DLP picture goes out, apparently all that needs to be replaced is a $300 projector module of some sort -- nowhere near as expensive as a plasma breakdown). Whatever type you get, one of the questions to ask is how much it will cost to repair/replace the main display if it "goes bad."