I have a very simple request here to implement, if it doesn't already exist, a way to filter questions by number of answers. This would allow you to look for questions with no answers at all (not just questions that have no accepted or upvoted answers, like the unanswered questions tab).
You can already do this using
answers:0 in the search.
Here are all questions with no answers, ordered by newest:
And here are all questions tagged sql-server with no answers, ordered by newest:
And here are all questions containing the word
foo, ordered by newest: