Try like this
Get-VM |Select Name,
@{N='Standby Response';E={$_.ExtensionData.Config.DefaultPowerOps.StandbyAction}}
And for a faster version, especially in big environments, you could do
Get-View -ViewType VirtualMachine
-Property Name
,'Config.DefaultPowerOps' |Select Name,
@{N='Standby Response';E={$_.Config.DefaultPowerOps.StandbyAction}}