Employee Benefits Review Checklist

I see many under- or incorrectly- utilized employee benefits. Components could include: should I buy espp? Am I getting the full HSA match? Am I getting the full 401match? Should I enroll in deferred comp? Is Dental insurance worth it? etc etc etc. My primary interest here is checking for free money that they're leaving on the table - matches, stock purchase discounts, employee discount programs, etc.