I have yet to see a high definition LCD or Plasma TV displaying a standard definition 4:3 aspect ratio signal that didn't look like crap. Do any exist?
I purchased a 42" Panasonic plasma and I hooked it up today; I don't have the HD receiver yet so I can only watch SD programs. I wouldn't know your standards for SD TVAD, but what I have been watching tonight looks very good to me, after making video adjustments.
I am also impressed with the stretch mode, called "JUST", this surprises me. It depends on what you are watching though. When watching some Karate on ESPN2, most of the viewing from the camera was away, it looked quite good. ESPN2 followed up with boxing and the announcers being near field of the camera, I don't like that as much.