What’s the budget? The 2019 & 2020 LG OLED’s are hard to beat. Very low input lag, true 120Hz (for 4K needs a hdmi 2.1 source which currently gpu’s don’t have). Also support Freesync & G-Sync.
Budget is probably your limiting factor here.
The Predator CG437K also VERY nice it can run 144Hz with dual Display-port cables, but my cousin just uses the 120Hz setting.