[mrbodoia]

My intention was that the "best" sort would be equivalent to "least partisan". Under this ordering, posts which have strong support from all three user groups are ranked highest (specifically, it's ordered by log(left_votes) + log(right_votes) + log(other_votes)). But perhaps I should change the name from "best" to something that better conveys the lack of partisanship.

I like the idea of a bubble index. So maybe when you login, the landing page shows you the partisan distribution of the posts you've read/commented on/upvoted, and you can see for yourself how deep your bubble is.