The video calibration tests offered on many THX DVD sets is a good, basic place to start. The dedicated Avia or Digital Video Essentials have much more elaborate test patterns. Avia is easier to use.
Most HD sets, whether DLP, LCD, or even CRT rear-projection are set way too bright and contrasty out of the box, however, most sets now have a "Cinema" type setting that in a dimly lit room will be far superior to the showroom settings, sometimes called "Dynamic".
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