calibrate it
TVs are not calibrated well when they are sold. They're normally way to bright with the contrast cranked up to much. This is done because they don't know which set will be unboxed for display, and when you're viewing them side-by-side the brightest looks better (in part because of how bright most show rooms are). When the brightness and contrast are to high then artifacts from image compression become significantly more noticeable.
A quick fix is to check the "video menu" for a "movie preset". A better fix is to get a calibrate source like this:
http://www.amazon.co...ay/dp/B000V6LST0/
