you left it on pause and come back from the backyard 2 hours later to find it stilll on and paused....your fucked).
That's pretty extreme. 2 hours once isn't going to be a big deal, and certainly not on newer sets. Burn in is commonly seen with ticker tape displays on stock channels from day traders who leave the same thing on ALL THE TIME. Also, your glass set can suffer from the same burnin problems, although it is more rare.
So what make/model did you end up getting?