I had an original Predator X34 (100hz) and was very happy with it for a very long time, then a break in about a year ago forced me to replace it.
The sane choices at the time boiled down to these
LG 34GN850 : 34" 3440x1440 160Hz IPS
LG 38GN950 : 38" 3840x1600 160Hz IPS (only 144hz is useable imo due to DP1.4 limitations)
Samsung Oddesy G9 : 49" 5120x1440 240hz VA
LG OLED48CXPUB : 48" 3840 x 2160 120Hz OLED
Havent done much research since but these all still seem to be more or less the best, there isnt really a great HDR ultrawide solution hence the inclusion of the 48" OLED CX
All the higher resolution options will require more GPU power to maintain similar frame rates so you may want to consider that too