Alienware 34 Gaming Monitor – AW3425DW, WQHD (3440×1440), 240Hz, QD OLED

You will be able to find cheaper MSI models but youre paying for the better build quality/warranty with Dell.
0.03ms, NVIDIA G-SYNC Compatible, AMD FreeSync Premium Pro, 21:9 1800R Curved, HDR True Black 400, USB-C, 3 Year Warranty
DCI-P3 99.3% color gamut, Delta E2 factory color accuracy, and VESA DisplayHDR True Black 400 certification. Delivers 1000 nits peak brightness and infinite contrast
Fully adjustable stand with tilt, swivel, and 110mm height range includes 2x HDMI 2.1, 1x DisplayPort 1.4, USB-C with 15W charging, USB-A/B 5Gbps ports.
For first time OLED buyers
Last gen QD-OLED is very easy to scratch, its not good in bright rooms and its glossy unlike IPS matte panels which makes it look better but reflections are more distracting.
This generation also has faint green/magenta fringing on text, I would recommend the new penta-tandem AW3426DW if you plan to do work/coding on it.