If you watch TV during the day, I agree that an LCD TV is better than plasma in your case, because plasma TVs have shiny screens just like old CRT models. However, some LCD TVs also have shiny screens, and Samsungs are among them. So even though Samsung LCD TVs are excellent, their shiny screens make them less than ideal for your situation. You need an LCD TV with a matte screen.
For you, I recommend a Sony LED-illuminated LCD TV. If you can afford it, the HX929 (seen here) provides LED backlighting with local dimming, which is the best type of LED illumination, and it comes in 46- and 55-inch sizes. Otherwise, any of Sony's edgelit models would probably suit you well, though I don't like LED edgelighting as much because of uneven screen uniformity, which is especially visible in dark scenes.
Another, generally less-expensive option is Vizio, which makes several LED-backlit sets under the moniker Full Array TruLED. Several models are available with screens measuring 47 and 55 inches.
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