Summary
List of latest HWs for VR/AR/MR I think is great:
Oculus Rift DK2, DaydreamHS, Google Cardboard, Vuzix Blade, Nreal, Sony Playstation VR

My preferred VR: Sony Playstation VR
My preferred MR: Nreal

There may be many great VR/AR/MR headset out there but below are some headsets that I have truly experienced and understood their greatness.

Oculus Rift DK2

Personally, I’ve used this for development purpose before. It is really easy to set up using unity. The API is also well documented.

DaydreamHS

Is this a cotton sofa? Is this a pillow? No, it is a VR headset. The impressive comfortable outlook makes the user feel comfortable even before wearing it, and this is also what makes people willing to try it out. I would prefer pressing cotton instead of plastic against my face.

Google Cardboard

Cheap, friendly, easy to set up. This invention makes the poor dream come true (although the quality isn’t the same). It also solves the most critical problems of VR: accessibility and affordability.

Vuzix Blade

This is a handy light augmented reality glasses that comes with a companion application, allowing communication with our smartphone and using other applications like email, messages and media player control.

Nreal (My MR preferred headset)

This simply looking glasses has a 1080p resolution, 60fps and 52degree field of vision. Besides being ultra lightweight, it looks just like ordinary glasses that you can wear it for a long period of time. The glasses itself weight 85 grams! (lighter than my glasses). It also has a package that comes with 3 degree of freedom touchpad and magnetic nose support that makes it easier to fit our face.

As it is like normal glasses, we can still see the outside world. This makes the usage slightly safer as we can avoid colliding onto nearby surroundings. However, Nreal requires a separate android pocket device to operate, but we can wear that on our neck or clip on the pocket for convenience purposes.

Lastly, the developer mentioned that they aim to develop handy plugging system in the near future that allows connection to any smartphone or PC via USB-C, and this is what makes me really excited about what I can do with it.
Sony PlayStation VR (My VR preferred headset)

First of all, this is the few headsets that will not mess up your hair due to lesser contact with your hair.

Versatile and easy to wear, this headset also allows easy head fitting – there is a button at the back of the headset that expands the headband, and another button on the front to adjust the screen position. This makes the headset fit comfortably as compared to the older headsets that use the rubber band.

While some people are afraid of looking ugly when wearing it, Sony PlayStation VR has a cool design on the outside – There are funky glowing lights when the device is on. This makes the user look cooler on the outside. Most importantly, those who wear spectacles like me can easily fit our glasses inside the headset due to it being spacious inside and adjustable as mentioned beforehand.

In terms of specifications, Sony PlayStation VR has a 5.7 inch full high definition OLED, a resolution of 960 x 1080, and a 100 degree field of view. Although these spec doesn’t match up well to the Oculus Rift, which features a 1080 x 1200 display, I personally don’t feel any significant difference in terms of quality experience.

Overall, it is generally cheap while not compromising on performance and quality and has a lower barrier of entry because it does not require a high-end pc to operate. A PS4 still works fine.