Depending on what you're looking for, especially on sizes, here are my two recommendations. I should also add that your best resource on this is rtings.com
. I'm going for a 1080p display first because it has frequently been said that 4K is not that noticeably visible until about 50" or larger, but I'm no expert, just an enthusiast.
Probably your best gaming TV at a smaller size/price point is the TCL40FS3800
. It's a smart TV, it has low latency (27.2 ms in and out of game mode), and it passes 5.1DD/DTS through the optical out (useful for hooking a game system/PC up via HDMI and sending 5.1 Dolby Digital/DTS out through the TV, not to mention smart apps). It's 40" and can often be found for $250-$275.
If you think that 4K/HDR is the future and you know you want it (this means you're going to be gaming on a PC with a strong graphics card, buying a PS4 Pro, or a Scorpio - do not believe the hype, XB1-S is cool but it's really a 1080p game system that plays 4K Blu-Ray, not a true 4K system in the least). If this is the case, it's pricier, but you'll want the Sony X800D
series, which comes in 43" and 49" flavors starting at about $600-$700. It's got 4K, HDR, it has a game mode with low latency (33 ms), great motion blur, great upscale of 720p/1080p content, and supports 1080p60 at 4:4:4 for PC gamers and 4K60 at 4:4:4 as well. It's the jack of all trades at a smaller size.