It recently occurred to me (thanks to a few e-mails I've received in the last few months) that many people shopping for monitors are completely unaware of the panel technology driving them and how it affects, not only their buying experience, but their user experience as well.
If you've read our Monitor Buying Guide then you're aware of the different types of panels your monitor can house. If you haven't read it, I certainly recommend you do, but if you'd actually like to get some work done today, you can get a small piece of it here.
The three main panel technologies currently used in modern LCDs are: Twisted Nematic (TN), Vertical Alignment (VA), and In-Plane Switching (IPS).
Manufactures make the vast majority of consumer monitors using TN panels. So, not surprising, TN panels are the cheapest of the three technologies to make. With a few exceptions, monitors that cost $300 or less will likely have TN panels.
The main advantages of TN panels are their fast--usually 2ms--response time and, of course, low price. Their major disadvantages are narrow viewing angles, relatively low brightness (usually), and inaccurate color reproduction.
Next up are VA (mostly seen as S-PVA) panels. VAs have improved viewing angles compared with TNs, better color reproduction, and they typically have a much higher maximum brightness. Also, they tend to have the lowest black levels of all three panel technologies.
Unfortunately, a VA panel's response time and input lag are not quite as fast as a TN panel and they can cost anywhere from $400 to $800, and sometimes more depending on the panel's size. Also, you can expect a VA-based monitor's profile to be wider than a TN's. Ultimately, VA's are much rarer than either TN or IPS in consumer monitors.
Lastly, we have IPS. IPS-based monitors are usually the most expensive; however, the new e-IPS panels cost as little as $300 for a 22-inch model. They also have the best viewing angles of all three technologies and produce the most-accurate colors; however, their blacks are not as deep as on VA panels.
IPS monitors are the slowest of the bunch in both response time and input lag.
With each monitor review I've done in the last year and a half or so, I've mentioned the type of panel the monitor uses; however, if you're interested in discovering what types of panels other monitors use, check out the panel search feature on TFT Central.