If refresh rate matters a lot to you in gaming, then you might want to pay attention to the brand-new S2417DG from Dell: a monitor spec'd at 165Hz. Well, as long as you're willing to cough up for a graphics card that can reliably deliver 165 FPS in your games!
As its model name suggests, the S2417DG is a 24-inch monitor, so for many, that might not be ideal - especially in an age where 4K and ultrawide monitors are sought after. But for those who are fine with 1440p, this monitor can help deliver ridiculously smooth gameplay, especially games that are not incredibly demanding, like Counter-Strike: Global Offensive or Dota 2.
Where high refreshes are concerned, there's a general lack of IPS-backed panels. There's no exception here: the S2417DG is a TN panel. While that might sound like a downside, many TN panels today are actually very good, though many still have poor-ish viewing angles.
Another important perk of this monitor is support for NVIDIA's G-SYNC frame-smoothing functionality. This requires the use of a modern GeForce graphics card, so this monitor really isn't designed for Radeon gamers. Alongside G-SYNC is a 1ms response time, 1000:1 contrast ratio, and a brightness of 350 cd/m2.
If you're playing a game on this monitor that manages to peak at 165Hz, then G-SYNC won't need to step in. But if you're playing a game that's really demanding - enough to dip below 60 FPS - then G-SYNC can jump in to make a substantial improvement without side-effects like tearing.
With such refresh speeds comes a bit of a higher price tag, with the Dell S2417DG coming in at around ~$570. But for those silky-smooth frames, the price of entry could be worth it. Just don't forget the super-fast GPU.