I am certainly no expert, but in general, there are several types of flat screen monitors. TN (twisted nematic) was the first LCD technology. They tend to be cheap and can have good refresh rates (good for gaming), but suffer from poor viewing angles, uneven backlighting, and color reproduction. IPS (in plane switching) monitors have better viewing angles and color reproduction, generally at the expense of a higher cost and lower refresh rates. PLS (Plane to Line switching) is a Samsung technology which is said to improve upon IPS. VA (Vertical alignment) falls generally between TN and IPS and is kind of a compromise between the two.
Ultimately, it depends on what you use the monitor for. I use IPS monitors as I don't game much on my Mac and I like the better viewing angles and color that IPS provides.