A LCD may be a lot cheaper now but it still costs about three times a CRT of comparable size. It therefore pays to know the LCD basics when you are buying an LCD monitor. Some of the points that you need to keep in mind are:
Aspect ratio: Normally, the width to height ratio of a computer is 4:3 but newer machines have wider formats too. These include 16:9 and 16:10. These wider monitors have been designed for watching movies or HDTV in wide format.
Contrast ratio: This specification tells you the difference in the light intensity of the lightest and the darkest colour. The higher the contrast ratio, the more will be the difference between the brightest white and the deepest black.
Digital and analog connections: LCDs convert analog signals into the digital equivalent before displaying them. This is why most have a graphic card with a DVI or a Digital Video Interface. This sends the signal directly to the monitor without any intermediate conversion. Most LCD monitors have excellent signal conversion capabilities.
Luminance: This is just an indication of how much brightness you can expect from the panel. Typically the luminance of a panel is expressed in nits or candelas per square meter (cd/m=). If you expect to use your display units for standard tasks 200 to 250 nits is adequate. However, if you want to watch either movies or TV, opt for a panel that has a capability of 500 nits.
Pixel-response rate: This shows how quickly a pixel can change color. This ability is measured in milliseconds. The LCD screens with faster response rate are less likely to suffer from ghosting or streaking of moving images. You need a maximum of a 12ms-to-15ms response time across the spectrum, if you intend gaming or watching either movies or TV.
Portrait/Landscape modes: Some LCDs can be pivoted so that the longer edge can become either horizontal or vertical. This feature is useful for desktop publishing, web surfing, and viewing large spreadsheets. This costs extra, so buy it only if you really need it.
Resolution: LCDs scale images and if the native resolution is not good to begin with, images will never look good.
Viewing angle: The LCD is made in such that you will get a better view if you sit at an angle instead of facing it directly. It's best to find which angle works best for you. Remember this angle criteria becomes a critical issue when the size of the panel increases.