The ASUS TUF VG27AQA1A is the one we would buy, and we have flagged it as our Editor's Choice rather than the mid-tier pick, because the price we track for the LG makes that call for us. The ASUS gives you 27 inches of 1440p at 170Hz on a VA panel ASUS rates at 3000:1 native contrast, which is the deepest black of any non-OLED here. You pay for it in dark-transition smearing and in viewing angles, and its stand tilts and nothing else.
The LG 27GN800-B is the IPS alternative, and the honest thing to know about it is its age: LG launched it in October 2020, on a BOE IPS panel rather than the Nano IPS used in LG's pricier UltraGear models. It is still a good monitor, and it is the only pick here certified for both FreeSync Premium and G-Sync Compatible. But at the price we have recorded for it, it is asking a large premium over the ASUS for viewing angles and IPS color, so buy it only if those are specifically what you want.
The Alienware AW2725D is the step that actually changes the picture. QD-OLED means per-pixel black and near-instant pixel response, and Tom's Hardware measured it above 111% of DCI-P3. The OLED caveats are real and permanent: static interface elements carry a burn-in risk over years, full-screen brightness drops as white coverage rises, and the triangular subpixel layout makes small text look slightly fringed until you adjust.
Basis: panel specs and sync certifications from the manufacturers, published measurements from Tom's Hardware and RTINGS, and owner reviews. We have not measured these panels, and every response-time figure in the spec tables is the manufacturer's own. Ratings score each product on the merits with price left out, so the premium pick always sits highest. The tier tells you where a pick sits on price, not how good it is.