It's no secret that Estonia has a desire to be a Nordic country. Using a Nordic cross flag has been discussed many times throughout history. There's a few options, which do you think looks best?
I kinda like the middle one the best, you really need to have blue-black-white in that order somewhere on the flag, to still represent the classic winter imagery of blue sky, black forests and white snowy fields.
The bottom one also contains that combination but is too similar to the Finnish flag.
Just a black cross with blue field above and white field below, essentially the current flag with the middle black band as a cross. Also effectively a less reich-y version of the last one in this list.
If you mean which one looks best in a vacuum, I'ma go with the last one. Very bold and eyecatching. But folks think it has a fashy vibe, so I can see not using it in the real world; in which case I like the third.