aspect ratio of the future

[Swarna Surjya Chakraborty]

Hi experts, What should be aspect ratio of the future 4:3 or 16:9 or 21:9?
There are contents available on all of these. Which format will ensure we have very little black borders vertically or horizontally so that we can use our entire screen viewport without stretch?

 

[technobhatt]

16:9 is already accepted worldwide for most common use for TV and Computer screen.
The biggest supporting reason is due to its capability of fitting all other popular aspect ratios comfortably under this ratio.
https://en.wikipedia.org/wiki/16:9

 

[prosenjit]

for cinema i would like the widescreen 2.35:1 anytime