There is some questionable advice and logic in some of the posts, based on my skimming. So, hopefully, this post will help to clarify a few things:
1) In no way can any TN panel ever be as good as an IPS panel or a decent VA panel, in terms of color/gamma consistency. It's impossible, because of the pixel type. TN panels have bad vertical gamma/color shift. It's the price you pay for the pixel type being the cheapest to make and, most importantly, the fastest to refresh.
2) TN panels are the fastest, but not all of them are overdriven well. LCD pixels need to be overdriven to reduce blur. The drawback is that if the overdrive is too aggressive you'll get artifacts that make graphics look bad, like trails.
3) VA panels, as far as I know (I stopped researching extensively a while ago) always have the worst response times in the darkest dark-to-light transitions, when compared with decently overdriven TN and IPS panels. This appears to be an unavoidable drawback of the VA pixel type. If this has finally been solved since I stopped extensively following monitor tech then that would be interesting to know. I doubt it, though. Even the fancy Eizo 24" strobing backlight 240 Hz gaming panel (really a satellite monitor for $5000 sold to gamers with grade B, or something less than A+, panels) struggled with these transitions.
4) A strobing backlight is critical if you want the least motion blur, but it can cause "eyestrain".
5) PWM vs. constant control backlighting. The former causes flicker. It may cause eye/brain fatigue, since it's literally a matter of shutting off the backlight and turning it back on again quickly constantly. The speed with which the refreshes occurs may make a big difference in terms of the amount of physical discomfort related to its use. I don't think there has been any scientific research into this. Constant control backlights don't flicker but they may have more difficulty with color shift related to brightness adjustments. Constant control backlighting became a lot more common once the public found out about PWM flicker, thanks to articles on sites like prad.de and tftcentral.
6) It was said that a 2000–3000 static contrast ratio in a VA panel is a red flag because other VA panels can go higher. It's not a red flag if you're seriously considering an IPS or TN panel, neither of which can get that level of contrast. The last time I checked, the best IPS and TN can do is a bit over 1000, like maybe as high as 1200:1. The lowest VA panel I recall seeing in recent years was around 2400:1.
7) VA panels are challenging for color-critical work because of their head-on black crush, a side effect of the pixel type. It is a fairly minor issue for people who don't do color-critical work. It is very minor when compared with the color/gamma shift of TN. However, some older VA panels did get quite washed out at wider angles, and had strong color shifts. They weren't as bad as TN is vertically, though.
8) IPS not only lacks the head-on black crush of VA but also has the widest viewing angle trueness to color/gamma. The bad sides of IPS are the reduced contrast, the polishing process involved in making IPS panels (which can negatively impact uniformity), and "IPS glow". IPS glow can be eliminated by the monitor maker adding a polarizer but they're all too cheap to do so anymore. VA panels have a much fainter deep violet glow.
9) Input lag is the most important criterion for competitive gamers doing fast-paced gaming. The nicest-looking monitor is bad news if it doesn't enable you to match your input timing with the output onscreen.
10) FreeSync and G-Sync. Look them up if you don't know what they are. If you don't know what they are, in enough depth to make an informed purchase, then you should read up. Although, look into the unbranded industry spec that addresses screen tearing.
11) For movies and slow-paced gaming (like Civilization), VA is the choice, no question. For the highest-speed most competitive gaming, it's TN, no question (with a strobing backlight, very low input lag, and 120 Hz at a minimum). For color-critical work, IPS is the choice, no question — unless you really need contrast, in which case you may want to consider using a calibrated OLED TV or something to make final adjustments related to contrast. OLED is likely to get burn-in or image retention if used as a computer screen but it doesn't have VA's black crush problem and it has even better contrast. Don't overestimate the importance of color accuracy as a gamer. Many males are partially red/green colorblind, too. If you are then you may want to artificially boost the red and green output of your panel anyway. I don't know if that helps with the colorblindness, though.
12) HDR. Read up about this. Eye-searing brightness might be a drawback for some but the 10-bit color could be nice enough. It seems than the industry is moving away from fake HDR schemes to a true standard that improves color rendering, grey precision, and increases the brightness. The last bit is, in my view, mainly to enable advertisers to irritate people more effectively with commercials.
13) Uniformity is important for color-critical work and for photographic work involving greyscale images. Contrast is important, but uniformity is also. The best pro screens have uniformity compensation tech that actually works. Some have the tech but it doesn't really do anything. OLED and plasma don't have such uniformity issues but they're not really suited for computer monitors because of retention and burn-in. Uniformity imperfection mainly involves gamma differences (darker and lighter areas of the screen surface).
14) Backlighting varies, in terms of there being edge-lit and multiple point rear backlighting. Edge lighting is cheaper but tends to be less uniform. One tactic monitor makers (but especially TV makers) often use is "local dimming". This involves a multiple point rear backlight, where some of the backlight is on and some of it is off, to increase contrast. Although these dimming schemes can increase perceived contrast they can also be noticeable.
15) Dynamic contrast is the contrast spec the industry has traditionally liked to peddle but it's deceptive. Stick with comparing static contrast ratios.
16) Panels typically come in 6-bit + 2 bits of FRC dithering, 8-bit, 8-bit + 2 bits of FRC dithering, and 10-bit. Anything above 10-bit, like 10 bits plus 2 bits of FRC dithering is probably overkill. For the tiny antiquated sRGB color space, which is the standard for video games and most consumer content even today, 6-bit color is fine. What's more important than the processing depth is the gamut (the range of colors) the backlight is capable of delivering. If it's 100% sRGB with smooth coverage then you're all set, even with 6-bit + 2 bits of dithering. This is, of course, if you don't mind minor shimmering effects from the dithering and don't need HDR's 10 bits. For color-critical work, you want an 8-bit panel at the minimum, but really should get at least an 8-bit + 2 bits of FRC panel. The color processing depth can mainly be thought of in terms of the smoothness of gradients — resistance to banding. However, more than one thing can cause banding. For color-critical work you want, at the minimum, around 100% coverage of the old AdobeRGB color space (bigger than sRGB but still inadequate). If you're going to be using professional printing it's ideal to have a panel that can cover the full gamuts of the CMYK print spaces.
17) Monitor speakers are trash. Ignore them.
18) Reduced blue light modes are nice to have, so you don't have to use f.lux. That software is annoying because it constantly shifts the color depending on the time of the day. Once you get used to the comfort from a warmer white point you'll probably never want to go back to the eye-searing cold bluish 6500K+ standard. Some panels ship calibrated even colder. A warmer white point is even nicer in dark rooms. Once you're warmer than 4700–5000K, though, you're really not worried about color accuracy so much as comfort. This is an example of why a non-graphics pro workload doesn't necessarily need color accuracy.
19) TVs can sometimes be good enough gaming monitors. Look for very low input lag, especially in any kind of special mode, like 120 Hz. Some TVs do very well in input lag at 60 Hz but are bad at 120. Also, don't forget screen tearing (FreeSync, G-Sync, etc.).
20) LCD performs best at its native resolution so try to pick the resolution that your system can handle. If you get more resolution than your system can handle then at least get what your next upgrade can handle. Otherwise, having 4K or more can be a drawback. I am a fan of the 32" 1440 format, personally. Remember, that when you sit further away from a screen the pixels seem smaller. If you sit far enough away you won't be able to see, for instance, any difference in quality between an 8K and a 4K screen. Yet, you're expending a lot more processing energy and storage space, let alone the price tags.
21) Curved or not curved. That is a question.
22) Wide screen, ultra-wide, or normal dimensions.
23) What is your budget?
24) Light anti-glare, strong anti-glare, semi-gloss, glossy but muted, shiny? These have all been options in the market. One Dell VA panel, for instance, was compared to a mirror because its untreated glass surface was so reflective. Another Dell had a strong "crystalline" look from the strong anti-glare treatment of the glass. Different people have different preferences about anti-glare levels and types. Physically etched screens (versus chemical coatings) are typically the most effective at reducing glare but also cause the worst crystalline effect. Strong anti-glare has lost popularity, although it's probably the best choice for powerfully bright office lighting — like big overhead fluorescent systems — and when windows are shining onto the screen.
25) The most competitive higher-speed gaming panel has these features: strobing backlight, TN, 120 Hz or better, very low input lag (including with 120 Hz or better mode enabled), pixels overdriven "just enough" (not too much overshoot), and screen tearing reduction tech like FreeSync. Some also like tech that reduces the depth of dark areas but I don't see why that can't be done in the video card or CPU. The monitor that is geared at more generalized entertainment: no strobing backlight, 120 Hz with low input lag, a VA panel with 2700:1 or better contrast (ideally 5000:1 or so) — properly overdriven. TVs with VA panels are generally quoted as having higher static contrast than computer monitors. Perhaps this has changed since I last checked, though. It seems that the monitors, though, lagged behind in terms of the sophistication of the VA pixel tech. The exception was the Sharp panel in that old 1080 resolution Eizo I mentioned that could reach 5000:1.
26) If you use HDMI, remember to switch it to full RGB range mode, not limited. I think the full is 0–255 and the limited is 16–255, so you lose some of the deepest blacks with limited mode. As far as I know the limited mode is made for TV use. However, it can be turned on by default in computer setups!
27) Color enhancement boosts don't add information. In fact, like sharpeners, they tend to reduce the information presented on the screen. Similarly, fancy software shader add-ins may seem neat but they may just be reducing the information level by boosting color and crushing the gamma. If your panel seems to lack contrast you can cheat by raising the gamma to a higher number. This makes things look more contrasty but you're throwing away detail in the process. You can also get the "make dark areas lighter to see your enemy" tech, at least in a limited manner, by reducing your gamma's contrast. Linear 1.0 gamma is the most "washed out" gamma setting, typically. It looks bad but perhaps it will help you see people in shadows.
28) Contrast adjustments on monitors usually shouldn't be messed with because they're boosting the RGB channels. It's better to calibrate the RGB channels separately.
29) You can't trust the human eye to do calibration. It adjusts itself to accommodate what it sees. For instance, if you switch your white point to 1900K (candle level warmth) it will seem really orange for a while. But, give it time and the red/orange will steadily become less "there". Your brain/eye adjusts for the extra red. You must use a colorimeter and software that gives good-quality results. This is if you want color/gamma accuracy. Even if you're not doing color-critical work it's nice to, at least, not have banding. Most monitors do not come very well-calibrated from the factory, although standards seem to have been increasing, at least in the prosumer and better market.
30) The best color work monitors have a programmable hardware LUT (look-up table). This enables calibration with less loss of presented information. It's less lossy calibration. LUT profiles, though, from what I've read, are less supported, in terms of what software will recognize the profile correctly, that the simpler, and more lossy, matrix color profiles. Perhaps things have changed?
That's 30 points off of the top of my head. I'm sure I've forgotten some things but I think I remembered the important stuff.
Also, watch out for BenQ/AUO because they have created a name for their pixel type that says "VA" in it but it's actually a variety of IPS. I think it's "AHVA". Why they did this is a mystery. VA means vertical alignment and IPS pixels are not VA.
PLS is another variant of IPS.
A-MVA (the common version of actual VA in recent times) used to have a competitor from Samsung called c-PVA. It was a cost-reduced variety of the old PVA type. PVA had some good points but I think pixel speed was not one of them. It was also, as I recall, a bit costly to make. c-PVA was inferior to it because of strong black crush and Samsung apparently couldn't keep up with the improvements to A-MVA.