Ordering by most plays or rating only works on a per song basis in iTunes. So, write an AppleScript to calculate some kind of per-artist (and possibly per-album) ranking. A simple implementation would be to sum the ratings of all the songs by each artist, or sum their play count. Alternatives include just an average of each artist’s song ratings or play count. But that would unfairly promote one hit wonders. ‘course, you could then sort by number of songs by the artist…
Worth playing with, anyway.