Let me disagree.
I would not call them "the best".
Because this is just to ambitious.

I would say - these are the people who somehow got my attention most often, and/or have their point of view (POV) most close to my POV, therefore are geting most of my sympathies. By manual curation, I hardly can see and read more than 20-30% of all new posts every day.
The number of posts, as well as the number of authors, are growing day-by-day, while each day still keeps ending after 24 hours.
As simple as that.