It's worth noting that these screens use different panel types. The Asus has a TN panel, the Dell has an IPS panel, the Samsung has a VA panel, and it looks like the Sceptre has a VA panel as well, judging by its contrast ratio and curve.
TN panels tend to be the weakest in terms of color accuracy and viewing angles, but they have slightly faster pixel response times than the other panel types. IPS panels tend to have the best color accuracy and viewing angles, but dark areas tend to glow a bit, hurting their contrast. VA panels offer far better contrast than the other panel types with dark blacks, and color accuracy and viewing angles tend to be somewhere between VA and IPS. Some VA panels can show a bit of purplish ghosting in certain scenarios though.
It's hard to pick an order to rank them, since it would depend on what you want out the screen, and the placement could change depending on one's needs. Here's a quick summary of things I noticed about each of them based on their specs though, in no particular order...
- Asus VG245H 24"
TN panel
75Hz with FreeSync
2 HDMI, VGA
2-watt speakers
detailed stand adjustments (tilt, swivel, height and pivot)
3y warranty
- Dell SE2717H 27"
IPS panel
75Hz with FreeSync
larger size
HDMI, VGA
no speakers
limited stand adjustments (only tilt)
1y warranty
- Samsung IT LC24F390FHNXZA 24"
VA panel
60Hz
curved
HDMI, VGA
no speakers
limited stand adjustments (only tilt)
3y warranty
- Sceptre C278W-1920R 27"
VA panel
60Hz
curved
larger size
HDMI, DP, VGA
3-watt speakers
limited stand adjustments (only tilt)
1y warranty
The Asus has some good specs overall, and is the only model here that offers decent stand adjustments. It has a TN panel, which would not be my first choice in panel type due to colors shifting when viewed at an angle, but it is likely still fairly good in terms of image quality, and has fast response times. It also has a slightly higher 75Hz refresh rate, as well as FreeSync, which would be nice if you have an AMD graphics card.
The Dell has an IPS panel for more accurate colors at the expense of slightly slower pixel response, and its a bit larger. It also has Freesync and a 75Hz refresh rate. The stand is underwhelming though.
Out of the two curved VA panel screens, the Sceptre may have better specs on paper, but in general, Samsung screens tend to be of higher quality, since they make their own panels. Sceptre, on the other hand, is more often considered a budget brand. This Sceptre screen is larger than the Samsung though, and it offers speakers and a DisplayPort connection. The Samsung has a better warranty though, and is likely built to higher standards. Both screens should have high, 3000:1 static contrast ratios, which is good, but they have lower 60hz refresh rates than those other screens, and no FreeSync.
Any of these are probably decent-enough screens for their price range. For gaming, those offering a 75Hz refresh rate could allow motion in games to look a bit smoother, particular if you have an AMD graphics card to make use of FreeSync.