Regardless of the type of TV you choose, the quality of the picture starts with the source. Digital cable on a bad TV can look better than antenna reception on even the best TV. Aside from HDTV, the best-quality broadcast source you can get is usually digital cable or digital satellite (Dish Network or DirecTV). Behind those is standard analog cable, then, finally, antenna. Quality varies from system to system, and some channels--usually premium ones such as pay-per-view or movie channels--look better than others. Broadcast sources cannot hold a candle to DVD, however, which will provide the best picture you can get without buying an HDTV.

Not everyone can watch DVDs all the time, so the quality you need depends on what you watch. Many nicer TVs, for example, have a vertical compression mode that allows them to display the full resolution of DVDs. That mode is useless if you don't watch many DVDs. Satellite and digital-cable subscribers would do well to grab a set with S-Video inputs to take advantage of that connection's superior picture quality. Component video inputs are generally reserved for DVD and provide the best picture you can get aside from HDTV. If you have a video-game console, you should choose a set with front-panel inputs so that you can connect and disconnect it easily to take it on the road.

You may have heard that the government is mandating that all television broadcasting be digital by a certain date in the near future. That doesn't mean you need to buy an HDTV now--or ever. Standard TVs will work fine after the switch to digital broadcasting (currently slated for 2006) because the external digital tuner, usually a satellite or cable box, can always output an analog signal.

If you're thinking about getting a bigger TV, you should seriously consider going high-definition. In addition to displaying the latest high-def digital broadcasts, HDTVs make regular TV look better and DVDs look spectacular. You can find 27-inch HDTVs for less than $700, and when you get to 36 inches and above, the price difference between standard and high-definition sets shrinks significantly.

If you do decide on an HDTV, the biggest choice is whether to stick with the standard, 4:3 aspect-ratio screen or splurge on the movie maven's dream, a 16:9 wide-screen HDTV. Again, it depends on what you watch most. Wide-screen sets are great for DVD fanatics and people who subscribe to HDTV over satellite, but most people still watch mostly standard-shaped TV programs and will probably prefer 4:3 HDTVs, even if it means black letterboxing bars above and below the picture. Remember that wide-screen TVs have smaller pictures when displaying 4:3 TV, placing window-box bars on either side of the image. Wide-screen sets also let you stretch the image horizontally to eliminate the window-box bars (which makes everyone look shorter and fatter) or otherwise broaden or crop the picture to fill the wide screen.

As we mentioned earlier, every HDTV has the ability to take regular antenna, cable, and satellite broadcasts and make them look a heck of a lot better. The process they use is called progressive scanning, or line doubling, because it essentially doubles the amount of picture information on the screen. Imagine horizontal venetian blinds over a window, closed halfway. Each horizontal slat is like a line on a regular TV, and if you sit too close, you can see the lines themselves making up the picture. Progressive scan closes the blinds, so all you see is the picture and no lines. A progressive-scan picture is much more stable and filmlike than anything you'll see on a standard TV.

True high-definition TV is still as rare as a forthright politician. Most major metropolitan areas have HDTV broadcasts, but the majority of HDTV owners don't have any way to view them. That's because most HDTVs actually don't contain high-definition tuners. The tuners, sold separately as set-top boxes, cost an extra $750 and up. Most people buy HDTVs for the improved picture when watching DVD and standard television, not for actual high-definition viewing. True HDTV comes in either 1080i or 720p formats, and it looks absolutely stunning--if you want to spend the money to watch it.

Even more expensive than direct-view and rear-projection TVs, ultrathin plasma and LCD screens are the ultimate in tomorrow's TV tech. LCDs are generally smaller, from 15 to 30 inches diagonally, while plasmas start at 32 inches and go from there. You can hang these TVs on the wall or even the ceiling, and their pixel-driven panels are perfect for use as computer screens. Most of these panels will accept HDTV signals, but only a rare few are powerful enough to display all the resolution of HDTV. Also, some plasma sets are susceptible to burn-in, where a static image displayed over a long period of time becomes permanently burned into the screen. Plasma owners need to make sure not to leave graphics and watermarks on for too long, especially if the set's contrast is set very high.