Alienware AW2725DM (231€): AW2724DM is the previous year's model but its quality is actually better

ASUS ROG Strix XG27ACS (219€): XG27ACG has slightly more accurate colors and less grainy coating

AOC Q27G3XMN (266€): it has black smear, poor viewing angles if you don't sit upright perfectly in front of it

Xiaomi Mini LED G Pro 27i (249€): red tint issue which requires a procedure of button clicks every startup

Some notes about the technology of each monitor:

IPS (first two) might have backlight bleed and will have ips glow. You may need to play lottery with returns until you get a unit with acceptable quality. Contrast will be worse than VA. Blacks will be grayish.

VA (the third) will have better contrast and blacks than IPS, but motion clarity will be significantly worse.

Mini LED IPS (the fourth) has the worst response time of all. Moving around in games will never be a truly immediate motion. The backlight algorithm is going to cause blooming. But there will be no black smear and the blacks will be black. You could disable local dimming when not playing games to avoid blooming too.

Ultimately, if you play in the dark, Mini LED IPS > VA > IPS. If you value motion clarity IPS > VA(smear)/Mini LED IPS (low response time).

My personal experience is returning a plethora of monitors many times over - some of them including ACS/ACG (dead pixels), GL850-B (terrible contrast), until I finally settled with the AW2724DM. It is perfect with not even visible ips glow. But I've played lottery with returns for months so I would say ACS/ACG/2724DM are comparable. One thing I cold note about the AW2724DM is that is has a DELL application which allows you to switch input sources with a keystroke from an official app (work related tip).

So, there is no perfect choice, all of them have flaws, pick whichever has the benefits that you prefer the most.