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What kind of HDTV you buy depends on your needs. Here's a rundown of the current display technologies. Each one has benefits and limitations, so make your choice based on the features most important to you.
CRT (Cathode Ray Tube) - Direct-view TVs consist of one large CRT tube coated on the front with phosphors. Rear-projection CRT TVs use three tubes, one each for red, blue and green.
Pros - The CRT offers the best black level and contrast of all video technologies. Rear-projection CRT TVs are a real bargain right now.
Cons - Rear-projection CRT TVs are not very bright, so you need a dark room. They look bad when viewed off-angle and the three tubes need to be converged occasionally.
Plasma - Despite their large screens (32 to 70 inches), they're ultra-slim. The least expensive plasmas are usually EDTV (480p) resolution, not HDTV.
Pros - Bright picture with excellent off-axis viewing angles. Better contrast than LCD TVs, though not usually as good as CRT.
Cons - Can suffer from burn-in when a static image is left on for extended periods, though most new plasmas include features to minimize this risk.
LCD (Liquid Crystal Display) - Like plasma, LCD TVs are also thin and can be wall-mounted. LCD TVs today are most common in sizes ranging from 13 to 30 inches.
Pros - LCD TVs don't' suffer from burn in. They are brighter than a CRT, but not as bright as plasma.
Cons - Some LCDs have poor off-axis viewing. At the moment LCD TV costs much more that an equivalent-sized plasma. LCD TVs usually don't have as good contrast as plasma and CRT.
LED (Light Emitting Diode)
There has been a lot of hype and confusion surrounding the introduction of "LED" Televisions. Even many marketing representatives and sales professionals that should know better are falsely explaining what an LED Television is to their prospective customers.
To set the record straight, it is important to note that the LED designation refers to the backlight system used in many newer LCD Televisions, not the chips that produce the image content.
LCD chips and pixels do not produce their own light. In order for an LCD television to produce a visible image on a TV screen the LCD's pixels have to be "backlit". For more specifics on the backlighting process needed for LCD Televisions, refer to my article: Demystifying CRT, Plasma, LCD, and DLP Television Technologies.
LED TVs are still LCD TVs. It is just that these new sets use LED backlights rather than the fluorescent-type backlights used in most other LCD TVs.
In other words, LED TVs should actually be labeled LCD/LED or LED/LCD TVs.
DLP (Digital Light Projector) - DLP rear-projection TVs are quickly replacing CRT as the best thing for big screens.
Pros - DLPs allow for a very slim and light designs. New chip designs offer good contrast and brightness. DLP TVs and projectors aren't susceptible to screen burn.
Cons - The lamp in a DLP TV will need to be replaced after a few years. Some people are able to see rainbow color artifacts caused by the TV's color wheel.
LCoS (Liquid Crystal on Silicone)
Like DLP, LCoS TVs are available in rear-projection format.
Pros - Like DLP, LCoS rear projection TVs are much thinner than traditional CRTs. They can be bright with high contrast.
Cons - LCoS is still very new and unproven. Like DLP, they have a lamp that will need to be replaced after a few years.
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