You might consider the AW2521HF twenty-five inch which I have had exactly one day. 240 Hz and 1 ms response time, should be good for gamers. I tend to buy gaming quality hardware (well, mid-range gaming) because I find that it ages better relative to the rest of the internet (for example, having more RAM than is conventionally considered necessary). Also I if I buy a bit "up" my son, when in town, doesn't bug me about the crummy quality of the household system.
The reason I got Dell is that my last couple of monitors have been Dell and over the years I have come to associate Dell with good quality and durability. I have had many years ago some ACER screens, I really didn't like them. Even in CRT days Dell monitors seemed a bit better.
My ten year old Dell is still going strong, but my wife wanted an extra monitor, so she got the old one, and I get this one.
At $330 it is above the $120 to $200 range that many of us would prefer to shop in. One of the criteria in my search is I really NEED
USB ports on the screen. I could probably figure out a workaround, but life is much easier when the screen has USB ports. And I really found my ACER screens, though less expensive, to be a downer for my personal use, gaming or no gaming.
I see that you are thinking about a very sizable screen and way above this price range. You might consider some of the larger Dell options. If they have a 25" 240 Hz and 1 ms response they probably have something else (in the Alien Ware line).
I pulled this new screen out of the box and ran the monitor tests here:
And was impressed. If there were dead pixels, I didn't spot them. I will add that this monitor has very solid stand (like all Dells I've had) and very good cable management arrangement.