Top performers are by default titled as Rock stars. See top performers right on the dashboard under the rock stars widget and also from the persons tab.
Reports show you performance scores by month and scores on a per job goal basis too.
Company performance report shows the top 10 individuals in the company.
Team reports show individuals outperforming others in the same team.
Evaluation record exports can give you an easy-to-use spreadsheet of scores to be analysed.