I think a big fact is the native resolution of the display your using, I'm using a 1440p monitor and it makes a world of difference when compared to a 1080p display, and I guess the results would be further improved with a 4k display. I'm using CRT-EasyMode-Halation shader with slight edits to the default settings
These are some quick shots i took....
I could make the scanlines a bit dark if needed
Those look nice. I think that was one of the better shaders I tried. My pics of Legendary Axe were also taken on a 1440p monitor (IPS). My other display for Retroarch is a 1080p Panasonic plasma.
A few shaders have pretty good results, but I found an unusual number of them to be disappointing or downright terrible. Generally even the best I tested fall quite short of the visual splendor of a nice, high quality CRT! Most people don't have a setup at home that allows them to do live comparison to see that it's not as close as it seems from still images viewed on modern displays (makes the CRT screenshots look closer to the fixed-pixel comparisons).
This isn't a putdown for anyone who likes Retroarch shaders and Framemeister scanlines. Overall they're good enough but having the real thing 15 feet away reveals their shortcomings and the fact that CRTs are still much better at being CRTs! I do agree the shaders will improve and will look even better as screen res goes up. I've always said I'll ditch the monitors once we get screen tech that perfect emulates multiple kinds of CRTs. Oddly enough the best artificial scanlines I've seen are on the HDMI N64... probably because of a combination of the blending effects and the N64's own soft graphics masking the artificial aspects of the lines. It looks really good.
I don't have a pic of MK at the moment, but I do have this one of Revenge of Shinobi with a life-like person on the title screen. Full size image taken with my phone, not perfect but captures a good amount of fine detail:
http://i.imgur.com/dos0XqL.jpg
Large Thumbnail of the above. Keep in mind Imgur's internal image resizing kinda blows. It dampens color vibrancy and kills a lot of the fine detail in a CRT picture. Take a look at the URL originals whenever possible.
And the shaders that are meant to mimic softer, bloomier CRTs really miss the mark. Full size image:
http://i.imgur.com/20KEfYp.jpg
And this is Retroarch on my 1440p Nexus phone using one of the better shaders. It's a screep capture but viewing it on my desktop LCD monitor it's fairly representative of what I see on my phone.
I actually do like the above on my phone's screen, but again it pales next to this:
http://i.imgur.com/0LMcsDA.jpg
This may seem trivial to some, but I liken all of this to the difference between hand-drawn Simpsons from the single digit seasons to modern day Simpsons with digital keyframes. At a glance of a static shot, maybe they're close enough... but seeing it in motion, in person, etc, there's a world of difference.