Monitor : 60 hz vs 144 hz when gaming ?

4k 144Hz monitors aren't available in reasonable prices yet. I have a 1440p 144Hz and it's quite good enough for me.

I'd pick whether you care more about resolution (I don't see the point in ultra-wide), framerate, or stuff like HDR,Gsync,etc since those are the cost drivers. If you think 75Hz is enough, you can often overclock a 60Hz one to 75Hz.

Generally, a screen that can handle higher resolutions and framerates would be better but that would only matter if you have the HW to run it, and if you want to use other things like free-sync. It comes down to what you can afford and run.

You are asking a really vague question so unless you want to compare 2 screens there isn't much point it. It's Obvious that a higher fps is better, and you can find the thousands of times people have explained it, but what monitor you should get is a different question.

FPS = hz so if your computer can handle it go with the highest possible. 1440p 144hz is pretty good combination in my opinion

Basically you would always want to have more hz so that you'd have more FPS. If your PC is strong enough to run games in 144 fps, you'll enjoy the switch to 144hz, though the change might not be that visible to everyone.

Personally, I prefer 4K@60fps. Why "only" 60 frames? Coming from a PS3 and a shoddy laptop which ran games at 30 or less frames per second, I discovered that in most gaming genres (apart from shooters) you don't need 144fps at all. There's no advantage over the fluidity of 60fps, as long as you're compensating that with a far better resolution.

As long as it's at least 60Hz you're good to go. For instance I had to deal for a few days with 4K@30Hz and it was a horrible experience.
You have to bear in mind that the higher the resolution and the refresh rate, the more stressful it is for your GPU to deal with it so you might need to invest in a better GPU to be able to cope with it.

For general use 60 FPS is more than enough unless you aim at competition level gaming that goes into the enthusiast territory. Also, if your display only supports 60 FPS it might be wise to use V-Sync otherwise you'll waste GPU resources for nothing. I remember having 6000 FPS in a game because it was uncapped and had no V-Sync option, practically maxing out my GPU for no good reason so I had to go into the NVIDIA Control Panel and force V-Sync for that game thus resulting in the GPU usage being next to nothing with the fans not even moving. The point is you don't have to base your usage only on synthetic benchmarks, you need to know your hardware and configure it properly according to your usage.

Tweaking your settings accordingly could bring you a lot more benefits than increasing your display refresh rate.

Thank you very much for the replies guys

i have a 1440p 144Hz monitor, with a GTX1070, its fantastic, WHEN THE GAME SUPPORTS IT, so far the only game where its objectively better and easy to use is CSGO, GTA V works fine too... but a lot of games new and old are locked to 60.

It's basically impossible, even with a 2080ti, to play at 144 fps AND 4K, it's either one or the other and in both cases you'll need a strong hardware.
That said, i prefer a 60 hz 4K monitor just because you'll notice way better a higher resolution than a smoother framerate above 60 fps. The difference is totally there between 60 and 144 (or 120) hz, but the benefits are smaller and require a good videocard to boot. Also not all games are compatible, or benefit, with 144 fps. Better invest that money in a good 4K freesync/gsync IPS screen with HDR support at 60 hz.

I don't think you can currently do 4K and 144Hz together, so you'll have to go with one or the other. I've got a 1440p (2k) monitor with 144Hz, and I love it for online shooters. If you're playing competitively or a lot of multiplayer titles, 144Hz could be a good choice, and if you are playing single player or less action-packed games the 4K resolution will look nicer. I'd also look for a monitor with Freesync (AMD) or GSync (Nvidia) support, as it will smooth out frame drops and generally look a lot smoother.