Field Value Report
Silverpop/IBM Watson has a function called "Field Value Report". Select a database field, run the report, and it will return all values that occur in that field. We used this function a lot, as it helped tremendously with database insights and clean-up.
Yes, I understand that as a workaround you could export to Excel and create pivot tables, but this is cumbersome and hits volume limitation very quickly.
I think this would be great addition to Marketo.