Flat Panel
2010

Why does digital cable look worse on a Flat Panel TV?
My parents recently bought a flat panel TV and connected their digital cable box to it. The picture actually looks worse on the new TV than it does on their regular TVs connected with the same box. My conspiracy theory is that this is on purpose so that people have to order HD service to get a better picture!
The picture still looks worse when I set the screen to "Standard" which does not stretch out the picture.
Ah, just because the cable is "digital" doesn't mean the video originally was! If the picture was squarish, not Wide Screen, it proably was old style analog video.
480i video is basically digitized analog video. Analog video wasn't all that great to begin with; after all, it is 1930s technology. The newer digital sets tend to be larger, too. So, when you put older analog video on a large screen, you magnify all the defects.
Just because something is "digital" doesn't automatically make it better. The cable companies are sort of distorting that fact.