1st and foremost... what is your max budget ?
next is what GPU are you using right now ?

Then get this Dell U2515H

its a IPS monitor with QHD

Resolution (number of pixels on the screen)
HD - 1280x720
Full HD - 1920x1080
QHD - 2560x1440
4K - 3840 x 2160

The higher the ppi (pixel per inch), the sharper the output.

LCD - Liquid Crystal Display
Can be divided into TFT and OLED.
Main components of TFT are panel and backlit.
While for OLED, because the pixel itself can provide emit light, therefore it doesn't have dedicated backlit unit to lighten up your screen.

TFT Panels
TN - Cheapest panel. Poor colour reproduction, poor viewing angle but have a fast response time
IPS - Expensive panel. Great colour reproduction, good viewing angle but slower response time
VA - Combination of TN and IPS. Colour reproduction ability lies between TN and IPS, but have a good black and contrast reproduction

TFT Backlit
CCFL - The typical fluorescent light in our house.
LED - More power saving.

So the monitor can be the following combinations :
- TN + CCFL (Old budget monitors)
- TN + LED (New budget monitors)
- IPS + CCFL (Old premium monitors)
- IPS + LED (New premium monitors)
- And VA monitors are rarer compared to TN and IPS.

I think you have been affected by the marketing terms too much. The current generation of monitors are mostly using LED backlit, but the divider between them is the quality of the panels. If you want a decent monitor, you should look for the one with IPS panel, not the one with LED backlit as backlit isn't the vital component to decide the output quality of a monitor. The one mentioned above comes with IPS panel.

HD is the old generation description of resolution. It doesn't explain how good the monitor is in terms of colour. So does LED.
Usually the shop will put those pictures with vibrant colour to attract the customers, however when you compare those TN monitors with IPS monitors, the difference is obvious, when you look at them from side.

To objectively determine whether a monitor is decent or not, you need equipment to determine the colour gamut of the monitor, as well as other aspects. But up to this stage, we don't need to see that, except for nitpicking comparison, say between 2 IPS monitors.

Not really there are others such as
XL2420G GSYNC

Dell 24 Ultra HD 4K Monitor – P2415Q

Dell UltraSharp UP2414Q Monitor with PremierColor

Are you doing colour sensitive task like colour grading or video editing?
If not, both are overkill for you.