I enjoy serendipitously learning new stuff based on answered questions on CV. But given the volume of questions a day, I end up only sampling from the newest questions, which are more likely than not unanswered.
I would like to sample from questions that HAD a bounty on them. That would increase the probability that the question was interesting (at least to someone) and was answered in detail!!
On that note, just filtering for questions that had ACCEPTED answers would also be useful.
EDIT: Thank you all. Great answers. And the use of badges is a great idea.