The detailed sales report (found under "Reports" and then "Detailed Sales Report) is a GREAT report. It has tons of detail and can be sliced up in an endless variety of ways. Due to its flexibility, we see it get a lot of use and probably overuse. We say overuse because when someone wants some summarized data it can be an inefficient way to gather it - it captures details of every single transaction line item that matches the filter criteria (typically - all sales between two dates). This can make it slower to run than a lot of other reports if you're wanting to report on a large number of sales.