What You Should Care About
Standard vs. high definition (HD): HDTV provides twice the detail of standard TV. It also costs at least twice as much, but now that most prime-time network programs are broadcast in HD, it's a good time to make the jump, says Joel Silver of the Imaging Science Foundation, which rates TVs and trains technicians.
Resolution: The higher the resolution, the sharper the picture. In a store, if you can see individual pixels (tiny squares) from your usual home-viewing distance, you need a set with a higher resolution.
Screen technology: The HD tube TV is the cheapest option. A rear-projection TV looks good if you sit right in front but gets dim if you move to the side. With flat screens, plasma TVs usually produce the best picture but can be too dim in well-lit rooms, where brighter LCD TVs work better.
What You Can Overlook
Contrast ratio: This term refers to the ratio of the brightest to the darkest shades that a screen can produce. Because the measurements are made in labs, they often don't apply to your home, says Silver.