Screens have recently become slightly more complicated to shop for. It is no longer recommended to buy an older style CRT monitor. These are the kind that are generally deeper than they are wide. New flat panel screens are the way to go. The quality of picture can be very important with a flat panel. It is recommended to first go by the size that you are looking for, and also by the Diagonal Dot Pitch.
Diagonal Dot Pitch: Similar to printers, screens have a value that is very important. The lower the dot-pitch number, the better the quality of screen. A good number is .26mm and below. .24mm is a very good quality. Anything higher than .26mm and you could experience headaches or fatigue when looking at the monitor for long durations.
Another option is to choose a glossy finish or a matte finish. This is just like the choice when developing photo prints. The rule of thumb is to consider where the screen will be located. If it will be in a room with windows or many bright lights, it would be best to get the matte finish to reduce the glare. If the monitor will be in a dark room, then glossy may make the image really look good, especially if you are watching video or looking at graphics. This is all subject to personal opinion.
Screens have recently become slightly more complicated to shop for. It is no longer recommended to buy an older style CRT monitor. These are the kind that are generally deeper than they are wide. New flat panel screens are the way to go. The quality of picture can be very important with a flat panel. It is recommended to first go by the size that you are looking for, and also by the Diagonal Dot Pitch.