Nir-Man

Well this was the cheapest I could find. But it is an average gaming monitor. https://www.amazon.com/Acer-G257HU-smidpx-25-Inch-Widescreen/dp/B00QS0AKVK?ie=UTF8&tag=amazon0606-20

Samsung Galaxy Tab S2 8.0

I know this topic is very much argued time after time. Most of the gaming LCD monitors (1080p, 144Hz) does not allow to manually update its refresh rate beyond 60Hz (via Nvidia control panel) due to the fact that HDMI 1.4 reference only stops at 60Hz. Think of a scenario where I can only use HDMI port to connect to a LCD and I happen to have HDMI 2.0 compatible GPU (also powerful enough for higher FPS). Do you know any 1080p monitor which you manage to manually update the resolution to support 120Hz via HDMI?

What are your requirements on refresh rate, response time and color reproduction? To be honest it's pretty hard to find a good gaming 1440p monitor (new) for 250 dollars.

It is hard to find a good gaming monitor with 144Hz (assuming you want 144Hz for gaming) for 21, 22 inch size. But if you you can go till 24 inches, these 2 may work for you. BenQ XL2411Z ASUS VG248QE

Check Acer's Predator XB271HU. It is an IPS display with 100% sRGB color gamut wihich happen to have a 165Hz rate. Plus it is G-Sync compatible too. But this one is with 4ms response time. The ones you have mentioned are well known for gaming too. So either should work just fine. As far as you are connecting the monitor through a DisplayPort or Dual link DVI, you shouldn't have any incompatibilities. Avoid HDMI though. Edited: And one more thing I have noticed, both monitors which you have mentioned are FreeSync ones which only works with AMD GPUs. If you wanna get full potential of your GPU, go for a G-Sync monitor but it will cost you more.

Portability is number 1 priority for me. I have first considered buying a gaming laptop, but similar performance laptops costs at least another $500 more. So I have searched Mini and Micro builds too. But non even come close to Alpha R2. For your comment on higher rates of CS GO and mobas, yes it definitely achieves 200 fps but it doesnt really matter since the monitor can only go up to 60Hz due to the limitation of HDMI 1.4. If I had an HDMI 2.0 compatible 1080p 144Hz monitor I wouldn't have any problem. But it is not possible at the moment.

I am planning on buying an Alienware Alpha R2 (with 960 GTX GPU). This only has HDMI out which supports HDMI 2.0 standard. Since there is no 1080p monitor which is compatible with HDMI 2.0 standard in the market, I still couldn't figure out the best monitor which suits its full potential. I know with current generation LCDs I could only go up to 60Hz only as HDMI 1.4 does not go beyond that point. Does 144Hz, 1ms would be overkill for Alpha R2? Any suggestions?

Well here is my two cents. HDMI 1.4 only supports up to 60Hz on 1080p or 30 Hz on 4K. HDMI 2.0 supports 60 Hz on 4K which in theory should support 120Hz on 1080p. But in order to achieve that, you should have a GPU which supports HDMI 2.0 and a monitor with HDMI 2.0 standard otherwise all you get is 60Hz. This is practically impossible at this point as even though Nvidia GeForce 900 series and above supports HDMI 2.0, there is no 1080p monitor which supports HDMI 2.0 in the market. Currently you could achieve higher Hz only through dual link DVI or through DisplayPort. Try to avoid HDMI which would limit your Hz rate