The single most important tip for anyone shopping for an LCD TV over Black Friday is this: Check the viewing angle.
Viewing angle is likely to be one of the biggest differentiators among the LCD TVs you'll see in the stores. Even TVs that have excellent picture quality—with great brightness, detail, black levels, and color—can look mediocre or worse when viewed from an angle. The picture can become washed out, hazy, or dim as you step off to the side, or move up and down (to simulate standin, sitting, and lying on the floor, for instance).
About one-third of the LCD TVs we tested recently showed at least some deterioration in the picture quality from off-angle, and on another one-third of the sets the picture deteriorated markedly. We're not talking extreme angles here, just a few steps off to the side, or up and down. Our Ratings of LCD TVs (available to subscribers) include a viewing angle score to show how each TV did. Unless everyone watching the TV will be close to front and center, we'd strongly recommend that you avoid models judged only fair for viewing angle. Sets scoring good might be suitable if there aren't big variations in viewing position, but a very good viewing angle is your best bet.
You can test viewing angle to some extent in the store. Try what I call "the couch test."
Stand 4 or 5 feet away from a 40- to 50-inch TV and move several feet to the left or right of center. That's comparable to sitting at the end of a couch in front of the TV. See if the images start to look more faded, if the screen darkens a bit, or if the colors lose vibrancy. Move a little farther away from center to see what the picture would look like from a chair off to the side of the couch.
This very informal test could give you some idea of the impact of viewing angle on the picture quality, though the very bright picture settings and vividly colored programs retailers usually display tend to minimize the problem. It's most noticeable in normal programming with indoor scenes featuring people. See if you can get the salesperson to change channels.
Incidentally, try the same thing with a plasma TV. You'll notice that the picture doesn't change at all. (For more help on choosing an LCD or plasma TV, see my recent post: Plasma or LCD TV? I vote for plasma.)
Hope this helps. Happy shopping! —Eileen McCooey