In the Top Topics section, there are some options for viewing the most popular threads from various periods, including the All-Time Summary, which can help for really popular threads board-wide.
However, there isn't anything I know of that breaks it down by forums or topic, which would indeed be handy. While site features are up to the Overlord to decide and implement, I know he's always interested in making ATS content easier for members and guests to find.
In the meantime, the ATS Search feature may be of some help, but then again, may not.
