What are the best control reports for Administrators to run on a weekly and monthly basis?

What are the best control reports for Administrators to run on a weekly and monthly basis and do any of these have to be downloaded from marketplace?

A Entity rights, data validation, user log activity, Meta data change audit, are some to checkout, along with workflow profile audit, And map transformation rules list.  The Dashboard calendar for routine tasks being run plus in solution exchange, marketplace Administrator Solution Tools plus excel add-in.