repadmin /showreps servername - Domain Controller replication status.
repadmin /replsum - replication status of all the domain controllers in the forest.
dsquery user -stalepwd <NumDaysSinceLastPwdChange> - Users Whose Passwords Are About to Expire
dsquery user -inactive <NumWeeks> - Users Who Have Not Logged On Recently
dsquery computer domainroot -inactive <NumWeeks> - inactive computers in the current domain
dcdiag /s:server-name - Test DC status (replication etc)
rsop.msc - (Resultant Set of Policy) Shows Group Policy settings that have been applied on a local computer
