This may be controversial, and may also be totally wrong (I’m no display expert), but I have a 55” Hisense U8K QLED and am still legitimately shocked at how black the blacks are. I can’t even tell if the screen is on or off if it’s just showing my black background. No light bleed or blooming, and inky rich blacks with incredibly smooth gradients. This screen convinced me that I’ll never need to shell out for an OLED.
Edit: in case you’re curious, I use it as the third screen in my PC setup, running at 144hz. It’s also my first experience with high refresh rates, and it has been a joy. Oh and the nits on this thing are something else. Ever been blinded by a sunrise in 4K HDR? It’s awesome.