I have a 42" Panasonic HD plasma that's 4 years old. No trouble with it ever. No burn-in that I can see, and I *never* use stretch mode for 4:3 material, but admittedly I don't watch as much as most people might. I watch DVDs way more than broadcast TV. But my DVDs are a mix of both widescreen movies and 4:3 box-set TV shows.

DLP's are the best bang for the buck when it comes to getting a big screen with an excellent picture. Unfortunately, while they are thinner and lighter than traditional rear projection sets, they are still bigger than LCD or Plasma.

I have a 52" DLP as my main set, and a 32" LCD in my bedroom.

Here is a link that might be useful: LCD-Plasma Comparison